What started as a war of words between China and Japan is fuelling real tension in the Asia-Pacific region

Source: The Conversation – Canada – By Kuan-Wei Chen, Researcher, Air and Space Law, McGill University; Bond University

In a now deleted social media post, the Consul General of the People’s Republic of China to the Japanese city of Osaka recently threatened to “cut off” Japanese Prime Minister Sanae Takaichi’s “filthy head.”

This graphic threat was in response to Takaichi’s suggestion that Japan’s Self-Defense Forces may exercise the right of collective self-defence and become involved in the event of a Chinese attack on Taiwan.

China has called on Takaichi to retract her “erroneous remarks.”

The Chinese outrage is apparently intensifying after Chinese military planes were accused of locking their radar on Japanese fighter jets near the Okinawa islands. China also imposed a ban on Japanese seafood imports.

China’s response has political and nationalistic undertones. China views Taiwan as an “inalienable part” of its territory, a reminder of the “century of humiliation” when the [island was ceded by Imperial China to Japan and became a Japanese colony in 1895].

A matter of history — and law

Even after the Second World War ended, sovereignty over Taiwan was never formally settled. China believes Taiwan must be “reunified” with the motherland, if necessary by force.

The number and intensity of Chinese military drills aimed at intimidating Taiwan have significantly increased in recent years. Chinese leader Xi Jinping has reportedly begun mobilizing the People’s Liberation Army for an invasion of Taiwan by 2027.

Taiwan’s status is complicated under international law. While it has a functioning government, population and defined territory — all necessary elements of statehood — much of the world does not officially recognize Taiwan as a state.

Most countries, including Canada and the United States, engage with Taiwan in a non-official capacity and simply “acknowledge” China’s insistence that Taiwan is part of China.

This respect paid to China is a matter of geopolitics and strategic ambiguity likely due to China’s global economic and political clout, and has little foundation in law.

International resolutions, declarations

China often asserts the 1943 Cairo Declaration as the legal basis for its claim over Taiwan. However, this unsigned media communiqué lacks legal force under international law, something pointed out by British Prime Minister Winston Churchill in 1955.

At the outbreak of the Korean War, U.S. President Harry Truman stated unequivocally that the “determination of the future status of (Taiwan) must await the restoration of security in the Pacific, a peace settlement with Japan or consideration by the United Nations.”

The 1951 Treaty of San Francisco, which ended the war between Japan and the Allied powers, is a legally binding treaty. While Japan renounced “all right, title and claim” to Taiwan, there was no mention of the People’s Republic of China — established only two years earlier — in terms of Taiwanese sovereignty.

The United Nations has never considered, let alone decided upon, the issue of sovereignty over Taiwan. China often cites the UN’s General Assembly Resolution 2758 in 1971 as another legal basis for its assertion of sovereignty over Taiwan. But that resolution only addresses the status of the People’s Republic of China as the legitimate representative of China and makes no mention of Taiwan.

The European Parliament and the parliaments of Australia, the Netherlands, as well as U.S. congress, have openly opposed China’s distortion of the UN resolution and attempts to exert undue influence over international organizations for political ends.

Japan-Taiwan proximity

Takaichi’s remarks are simply a reiteration of the late Japanese Prime Minister Shinzo Abe’s remarks that “a Taiwan emergency is a Japan emergency (台湾有事は日本有事).”

This is no surprise since, at their closest point, Japan and Taiwan are just over 100 kilometres apart. Japan’s deployment of anti-air missiles on the Okinawa prefecture’s Yonaguni Island and long-range anti-ship missiles at the mouth of the Miyako Strait are clearly aimed at countering a potential Chinese offensive.

The site of the largest American Air Force base in East Asia just a 90-minute flight from Taiwan, and is similarly already gearing up for a potential Chinese missile attack amid rising tensions.




Read more:
Why a row over military bases on Okinawa spells trouble for US-Japan relations


Taiwan itself is situated at the crossroads of vital maritime and aviation routes, and manufactures more than 70 per cent of the world’s microchips.

If China opts to blockade or attack Taiwan, it will severely impact the world economy since a fifth of global maritime trade, valued at $2.5 trillion, transits through the Taiwan Strait.

It’s in no one but China’s interests if the Chinese mount an attack, and certainly it’s not the will of the 23 million inhabitants of the independent island nation who enjoy some of the highest levels of political and civil liberties in the world.

The U.S. continues to bolster Taiwan’s defence to deter a Chinese attack since Taiwan’s security is pivotal to America’s strategic standing in the Asia-Pacific region and the world.

Global peace and security

With great power comes great responsibility, and this is true for all states. Threats of invasion, the use of force and non-peaceful means of settling disputes are all prohibited under international law. Undiplomatic rhetoric and distortions of history and the law is also detrimental to peace.

If Taiwan truly is a part of China, then there would be no need for an invasion or threats to “crush” any foreign interference. Through its wolf-warrior diplomacy and shows of force, China is in effect globalizing the Taiwan issue.

As the recent G7 statement states, the international community has “an interest in the preservation of peace and stability across the Taiwan Strait” as China’s military drills and threats of war jeopardize “global security and prosperity.”

In a world beset by conflict in the Middle East and an enduring war in Ukraine, tensions are again heating up in East Asia. Will cooler heads prevail?

The Conversation

Kuan-Wei Chen is the recipient of a Australian Government Research Training Program scholarship.

ref. What started as a war of words between China and Japan is fuelling real tension in the Asia-Pacific region – https://theconversation.com/what-started-as-a-war-of-words-between-china-and-japan-is-fuelling-real-tension-in-the-asia-pacific-region-270434

Why Mark Carney’s pipeline deal with Alberta puts the Canadian federation in jeopardy

Source: The Conversation – Canada – By Stewart Prest, Lecturer, Political Science, University of British Columbia

The recently struck memorandum of understanding (MOU) between Canada and Alberta is a high-stakes strategy that risks deepening already deep divides in Canadian politics.

While the MOU touches on a number of issues, at its heart is a shared vision for a new pipeline from Alberta to British Columbia’s protected northern coast.

In effect, the deal offers a quid pro quo: Ottawa agrees to relax a range of federal environmental regulations — including a ban on tanker traffic in B.C.’s north — and to support a pipeline in exchange for a commitment from Alberta to eventually increase the price of carbon on industrial emissions in the province to $130 a tonne.

It’s a vision negotiated without the involvement of either the B.C. government or the Indigenous Peoples affected by the plan. While the agreement calls for consultations with both groups, they are relegated to the status of secondary partners, with concerns to be addressed in the execution of the plan outlined by Ottawa and Alberta.

A policy solution for an identity issue

The deal is clearly meant to bridge the gap between populist voters centred in the Prairie provinces and the rest of the country. But both the content and the process risks widening that gap, even as it deepens divisions elsewhere in the country.

Simply put, Prime Minister Mark Carney is trying to find a policy solution to an identity problem, and doing so by picking sides rather than neutrally facilitating agreement.

It’s part of the polarized, populist identity in Alberta, in particular, to oppose Ottawa and Liberal governments. In fact, when Alberta Premier Danielle Smith referred to the MOU in front of the United Conservative Party (UCP) convention, she was roundly booed. Rather than being hailed as champion who had achieved valuable policy concessions, she was greeted as a traitor to the cause.

Given the rude reception, it’s not surprising that in recent days Alberta has sought ways to limit its environmental commitments.




Read more:
How ideology is darkening the future of renewables in Alberta


Playing favourites in the federation

Over the longer term, the agreement risks legitimizing the narrative of “Alberta aggrieved” by treating it as a distinct, sovereign jurisdiction entitled to special treatment.

In fact, the trappings and language of the agreement seem to reinforce the idea that “Alberta” is a natural negotiating partner with “Canada” rather than part of Canada.

The MOU’s signing ceremony in Calgary — not the provincial capital of Edmonton or Ottawa — bore all the hallmarks of international treaty-making, complete with flags and a formal text in both official languages. The symbolism reinforced the image of the deal as a kind of grand bargain between Ottawa and oil country.

While the federal government often strikes deals with provincial governments, this situation is quite different. It’s a deal only with Alberta but it primarily involves British Columbia. The agreement therefore elevates Alberta to the level of a quasi-sovereign jurisdiction to be treated as an equal with Canada. B.C., site of any future hypothetical pipeline terminals, has been rendered a deal-taker, not a deal-maker.

Unfortunately, that’s not how the federation is supposed to work. Just because the federal government has ultimate jurisdiction doesn’t mean other regions don’t get a say. It’s hard to imagine the federal government striking a deal with Ontario about what should happen in Québec without Québec’s involvement.




Read more:
Alberta has long accused Ottawa of trying to destroy its oil industry. Here’s why that’s a dangerous myth


B.C. fury

B.C. Premier David Eby was accordingly furious with the federal government’s approach before the deal was announced.

Since then, while pointing out weaknesses in the deal, the NDP premier has also been at pains to show his willingness to work with Alberta on workarounds, including an expanded Transmountain pipeline or another pipeline that would leave the oil tanker moratorium in place on B.C’.s northern coast.

In leaving Eby out of the conversation, the federal Liberals have alienated a natural ally in their pursuit of economic development, forcing the premier to defend B.C.’s status within the federation, the rights of the province’s Indigenous communities and the province’s protected northern coast and Great Bear Rainforest.

Constitutional obligations to consult

Even more telling is the united reaction of First Nations. The Assembly of First Nations has unanimously voted in favour of a motion calling for the MOU to be scrapped. In fact, the federal government may have put itself in legal jeopardy over its failure to consult prior to the MOU.

At some point, it will likely have to explain in court how it could be serious about consulting in good faith with Indigenous Peoples in accordance with its obligations under Section 35 of the Constitution Act when the MOU gives the appearance of approving the project in principle before such conversations even begin.

Offering ownership stakes to Indigenous groups in a project devised without their involvement is not consultation. Simply put, unless governments can show they’re open to amending their plans in light of information they receive during consultations, they risk falling short of their obligations.

Cracks in the Liberal coalition

While polls suggest a majority of Canadians support the idea of a pipeline so far, the Liberals’ own coalition shows some signs of fraying.

Former environment minister Steven Guilbeault’s resignation from cabinet over the deal, along with the resignations of multiple environmental advisers to the Liberal government, suggest the party’s reputation for environmental progress has taken a hit given the slow and fuzzy approach to climate action outlined in the MOU.

Other federal parties sense an opportunity. The Bloc Québecois has strongly denounced the deal and has offered to support B.C. in its campaign to defend the province’s autonomy. The move underscores the sensitivities that remain in Québec around issues of provincial rights.

Even more tellingly, federal Conservatives, perhaps initially dismayed by a deal uniting federal Liberals and Alberta Conservatives, are now putting a motion before the House of Commons asking it to endorse the government’s position on the MOU and make good on its commitments. The Liberals, for their part, have vowed to vote against the motion, arguing that it only endorses part of the MOU.

In effect, the Conservatives are seeking to turn the government’s own MOU into a wedge issue against it. The Conservatives will likely continue to press the issue going forward given how the idea of a pipeline at any cost unites Conservatives and divide Liberals. Liberal MPs in B.C. and Québec, in particular, will also likely feel torn between loyalty to the party and deference to the views of constituents opposed to the deal.

In short, a pipeline intended to unify threatens to throw divisions into even sharper relief — even within the Liberal Party itself.

The Conversation

Stewart Prest does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

ref. Why Mark Carney’s pipeline deal with Alberta puts the Canadian federation in jeopardy – https://theconversation.com/why-mark-carneys-pipeline-deal-with-alberta-puts-the-canadian-federation-in-jeopardy-271072

How Canada’s emergency communications still exclude Indigenous languages

Source: The Conversation – Canada – By Sara Wilson, PhD Candidate, Communications, Simon Fraser University

When life-saving information is not provided in a language people understand, it can delay protective action and put communities at unnecessary risk.

This was evident during the 2023 Yellowknife wildfire evacuation, one of the largest climate-related displacements in Canadian history, when nearly 20,000 residents were ordered to leave the city of Yellowknife with little warning.

Despite the Northwest Territories (N.W.T) recognizing nine Indigenous languages under its Official Languages Act, emergency alerts were issued only in English and French. For Indigenous-language-first speakers from the Yellowknives Dene First Nation and neighbouring Indigenous communities — particularly Elders — this meant relying on relatives, radio hosts or social media to interpret urgent instructions during a fast-moving wildfire.

At the very moment when clarity matters most, official alerts are not delivering.

Indigenous languages, though acknowledged symbolically in legislation, are not implemented in emergency communication protocols. This structural imbalance reflects a longstanding colonial assumption that English and French are the default languages of safety, even in regions where they are not the languages most widely spoken.

The recent magnitude 7.0 earthquake in the Yukon was the strongest on Canadian soil in 79 years. While there were thankfully no reports of injuries or building damages, the incident highlights the urgent need for an efficient emergency communications system.

Emergency alerts through a colonial lens

For my master’s thesis on the inclusion of Indigenous languages in emergency messaging, I examined public communications, government documents and after-action records. I found that the absence of Indigenous-language alerts was not a technical failure, but a predictable outcome of systems designed without Indigenous-language access in mind.

The scale of linguistic diversity in Canada underscores why this matters. According to Statistics Canada, more than 189,000 people speak an Indigenous language at home and more than 243,000 report being able to speak one.

During the Yellowknife evacuation, many residents — nearly one in five of whom report an Indigenous mother tongue — waited for translated information to appear on Facebook or relied on community broadcasters to interpret English alerts, causing delays that can be significant when roads, flights and services are rapidly shifting.

Policy choices and communication strategies during emergencies can have immediate and profound consequences. But this isn’t just a technical gap, it’s part of a much longer history of exclusion — one that continues to undermine Indigenous safety.

What international disasters teach us

After the 2011 Tōhoku earthquake and tsunami in Japan, researchers documented that unclear or linguistically inaccessible messaging contributed to evacuation delays, especially for those relying on informal interpretation networks.

In Aotearoa New Zealand, civil defence messaging routinely includes te reo Māori as part of national commitments to shared authority and revitalization. In Hawaii, emergency communication systems were strengthened after the 2018 false missile alert, and alerts are now issued in both ʻŌlelo Hawaiʻi and English.

While Canada’s context differs, the lesson is consistent: people act more quickly and confidently when emergency instructions are delivered in languages they understand. Nunavut, for example, issues emergency alerts in Inuktut using pre-translated templates and partnerships with Inuit broadcasters, demonstrating that multilingual alerting is entirely feasible with political will and basic planning.

Canada’s National Public Alerting System (NPAS), which sends alerts to phones, televisions and radios, currently supports message delivery only in English and French. There is no federal mechanism requiring or enabling translation into Indigenous languages or into widely used newcomer languages such as Punjabi, Mandarin or Arabic.

According to the Canadian Radio-television and Telecommunications Commission, 1,307 broadcast and wireless immediate emergency alerts were issued in Canada between 2019 and 2022. Despite this volume, none were issued in Indigenous languages.

In recent years, in Lytton, West Kelowna, Manitoba and across the North, wildfire seasons have reminded us that climate hazards are accelerating. If alerts are to do their job, they must be intelligible to the people who need them most. That is what linguistic equity means in practice.

Officials often claim translation takes too long, yet the technology and methods already exist. Pre-scripted templates, partnerships with community broadcasters and training for emergency managers could all be implemented now.

What’s missing, it seems, is policy direction and the will to act.

Reimagining a safety system for everyone

The same logic applies to newcomers building lives in Canada. If a wildfire or flood order arrives in a language someone cannot read, people are not safe.

Multilingual communication is not political correctness; it’s competent governance. People cannot protect themselves from threats they cannot understand. A multilingual alert system would reimagine safety through inclusion, rather than just cluttering screens with text. Policies of exclusion, especially in this context, put lives at risk.

Responsible use of AI translation tools could also help generate alerts in multiple languages, but always under Indigenous and community oversight to ensure accuracy and cultural integrity.

Canada has committed to both reconciliation and climate resilience, yet neither goal can be realized if life-saving information remains accessible only to those fluent in English or French. Whether future wildfire seasons unfold with safe and timely evacuations may depend on whether Indigenous Elders, Indigenous-language-first speakers and multilingual families can comprehend the alerts intended to protect them.

No one in Canada should be left in danger because of the language they speak.

The Conversation

Sara Wilson does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

ref. How Canada’s emergency communications still exclude Indigenous languages – https://theconversation.com/how-canadas-emergency-communications-still-exclude-indigenous-languages-267193

The price of belonging is inconvenience. Are we still willing to pay it?

Source: The Conversation – Canada – By Andrea Carter, Adjunct Faculty in Industrial and Organizational Psychology, Adler University

“Inconvenience is the cost of community” has become somewhat of a social media mantra for people looking to rediscover what belonging and community actually require.

For years, many have embraced the idea that people can have connections without co-ordination, community without commitment and relationships without the friction of difference. But belonging doesn’t work that way because human interdependence has never been without friction.

It asks us to show up when we’d rather stay home, stay in conversations we’d rather leave and to rely on people whose presence and beliefs grow our capacity to care beyond ourselves.

This inconvenience is part of the social infrastructure that holds communities together. My recent research suggests that when five core “productive frictions” are eliminated from that infrastructure, we strip away the very forces that keep communities strong, productive and together.

Three overlapping epidemics

Three converging epidemics now demand our attention, each pointing to the collapse of community infrastructure.

The first is loneliness. A World Health Organization report released in June found one in six people are affected by loneliness, with recent data from Canada and the United States showing increases since 2024.

Loneliness is linked to roughly 100 deaths every hour — about 871,000 a year — rivalling smoking in its mortality risk.




Read more:
Loneliness could kill you


Contributing to this issue is the widespread uptick in familial estrangement. Up to 130 million North Americans are estranged from a close relative, with 35 per cent involving immediate family members. Families often estrange members who are “inconvenient”: those who are different or who challenge repetitive traumatic family dysfunction.

The U.S. has approximately twice the rate of parent-child estrangement as Europe, a pattern researchers tie to a cultural emphasis on individual autonomy over family obligation.

The second epidemic is workplace toxicity. This year, 80 per cent of U.S. workers described their workplaces as toxic, up from 67 per cent in 2024, and cited it as the primary driver of poor mental health. Gallup’s global data also shows that stalled employee engagement has cost the global economy US$438 billion in lost productivity.

This is happening despite employers investing billions in wellness apps, engagement programs and other strategies. Many organizations are pouring money into individual coping tools while systematically removing the very infrastructure needed for community.

The third epidemic is an unprecedented global decline in civic and employer trust. These are not separate problems. They are all interconnected by a single root cause: the dismantling of social infrastructure that builds cohesion and belonging.

The cost of convenience

A recent study examined emotional intelligence scores from 28,000 adults across 166 countries and uncovered an alarming trend: global emotional intelligence has dropped nearly six per cent between 2019 and 2024.

Researchers call this an “emotional recession” because our shared emotional resources are shrinking in a pattern similar to an economy in a downturn. The steepest declines occurred in intrinsic motivation, optimism and a sense of purpose; three capabilities that help us to keep moving forward, hopeful and willing to invest in relationships.

Many blame “convenience culture.” Convenience culture prioritizes comfort and efficiency over collective responsibility. It often reduces human interaction to what’s easiest rather than what’s meaningful.

Digital platforms promise connection without commitment, comfort without consideration and belonging without mutual accountability. Algorithms reduce exposure to difference by curating belief-aligned feeds and allowing people to retreat from the discomfort that growth requires.

The messy, time-consuming interactions that build trust and interdependency — like the tense moments when colleagues work through conflict rather than agree or look away — are disappearing. We have optimized away the inconveniences that create interdependence, then wonder why people feel so alone, emotionally raw and incapable of handling difference.

As such, a fundamental distinction has been lost: belonging is not the same as fitting in. Fitting in is passive; it accommodates what meets the requirements, provides minimal access and enables you to stay as long as you comply. Fitting in is both conditional and transactional.

Belonging, on the other hand, is active and reciprocal. It asks something of you and the community that receives you. Both parties must adjust, accommodate and be changed by the relationship. That mutual obligation is exactly what convenience culture does not tolerate and precisely what builds trust, respect, commitment and the emotional resilience we are losing.

Five productive inconveniences

My research on workplace belonging identifies five “productive inconveniences” that make real community possible. Here’s how you can bring them into your own life:

1. Costly commitment: Real community is a two-way street. Be willing to put the group’s needs ahead of what’s easiest for you, but make sure this burden doesn’t fall on the same people every time. When only some people have to invest, being part of the community doesn’t mean much.

2. Co-ordinated time: Strong relationships need time to form. When calendars are full, try to make the effort to see people in person. Texts and emails are helpful, but they cannot replace real presence.

3. Navigating difference: Try to maintain relationships with people who see the world differently from you rather than retreating when your views are challenged. Learning to listen, respectfully disagree and stay curious in moments of conflict are what stretches you and makes your community stronger.

4. Conflict repair: Healthy relationships mean taking responsibility and accountability to work through conflict rather than just discounting or disengaging. Instead of unfollowing or walking away, have the hard conversations that allow relationships to survive and grow.

5. Mutual need: Belonging demands interdependence. Ask for help when you need it, and be willing to be needed in return. Doing everything alone is another form of isolation. Mutual reliance is what turns a group of people into a real community.

Choosing people over convenience

Leaders, whether in families, workplaces or communities, must learn to distinguish harmful barriers such as discrimination, exclusion and bureaucratic waste from essential inconveniences that build the muscle of belonging within a community.

The “emotional recession” study emphasizes this: people with higher emotional intelligence were more than 10 times more likely to have strong relationships, be effective in what they do and experience well-being in their lives.

The data suggests that investing in building emotional capacity and the productive inconveniences that develop it pays measurable dividends for individuals and organizations alike.

Community is not built solely through connection. It is built through interdependence, and interdependence is a human infrastructure that is deliberately inconvenient.

Every time we choose people over convenience, we invest in community. The real question in our homes, workplaces and democracies is whether we’re willing to pay that price.

The Conversation

Andrea Carter is an Adjunct professor at Adler University. She is also the CEO of Andrea Carter Consulting and the founder of Belonging First Methodology™.

ref. The price of belonging is inconvenience. Are we still willing to pay it? – https://theconversation.com/the-price-of-belonging-is-inconvenience-are-we-still-willing-to-pay-it-270778

Internationally experienced teachers: An overlooked resource to address teaching shortages

Source: The Conversation – Canada – By Gloria Ramirez, Associate Professor of Education, Thompson Rivers University

The increasing teacher shortage is a concerning global crisis. It will reach a shortfall of 44,000,000 teachers by 2030, according to the United Nations Educational Scientific and Cultural Organization.

From rural and remote school districts struggling to recruit staff to urban districts scrambling to cover classrooms, the signs are everywhere: unfilled positions, growing reliance on uncertified substitutes and an overextended workforce.




Read more:
Solving teacher shortages depends on coming together around shared aspirations for children


Canada is no exception. Ontario anticipates a full-blown shortage in core areas like French immersion by 2027. In British Columbia, uncertified teachers filled an estimated 20 per cent of teaching positions in the Peace River South district during 2023–24.

Teacher shortages are concerning because study after study has shown teaching quality is the most important in-school factor for student learning and well-being.

Yet, as our research is examining, internationally educated and experienced teachers (IETs) remain sidelined, underemployed or forced into careers outside education.

Ten years ago, a report by the Council of Ministers of Education, Canada noted that
thousands of internationally educated teachers apply for certification in Canada each year.

In our ongoing study with IETs in the B.C. interior, and in our work there, we’ve seen that many IETs have masters degrees or PhDs.

Findings from a 2024 study conducted on behalf of B.C.’s Ministry of Education and Child Care revealed systemic barriers to certification in the province for internationally educated and experienced teachers, including long wait times, unclear application procedures and high costs. The study included more than 730 survey responses and numerous interviews.

Barriers to teaching

Many internationally experienced and educated teachers who participated in the B.C. ministry study expressed frustration. Some considered abandoning their goal of teaching in B.C. altogether.

Key obstacles included requirements such as completing a new practicum and taking additional coursework at Canadian universities. Many study participants perceived these additional requirements as redundant and exclusionary given their prior qualifications and professional experience.

This begs the question, why are highly qualified IETs less able to secure teaching jobs in Canadian public schools?

Canadian teaching standards

The argument made by Canadian credentialing bodies is that their processes are in place to protect Canadian professional teaching standards. No one would argue with the importance of maintaining high standards, particularly in an education system highly regarded around the world, with students ranking comparatively highly on international tests.

One could argue that underneath the surface, these reasons mask unconscious biases that few are willing to recognize and acknowledge. Some researchers have said IETs are viewed as inexperienced, insufficiently attuned to local contexts or suspect. Their education systems are often seen as less rigorous and their professional identities as somehow inferior. There have been calls to use a more personal approach to better assess their qualifications.

The demographics of internationally educated and experienced teachers mirror the diversity of Canadian classrooms. Despite diverse Canadian classrooms, the teaching workforce remains predominantly white. The systemic distrust for internationally educated and experienced teachers comes at a steep price.

Students lose out on the diversity of perspectives and the cultural wealth these professionals bring. Schools miss out on teachers fluent in multiple languages, familiar with global education and research — and ways of teaching experienced in contexts of migration, displacement and resilience.

Ongoing research

Our ongoing study examines the experiences of 11 IETs who are participating in an orientation to Canadian kindergarten to Grade 12 education course and learning in K-12 classrooms in an interior city of B.C.

Early data from interviews with these study participants, teacher mentors and district administrators confirms the benefits of integrating IETs into our classrooms. Students in K-12 respond positively to seeing a teacher in the classroom who looks like them.

Many of the IETs participating in our study have moved from large metropolitan areas in their country of origin. Their ability to move from cities such as Shanghai, Manila, Jakarta, Delhi, Tokyo — with recorded populations of well over 25 million — to a small semi-rural urban centre of less than 100,000 people shows great adaptability.

While the adjustment requires a reorienting of thinking, these IETs do adjust, demonstrating adaptability. They come to love the open space and access to nature that Canada offers. They also value the sense of community found in small cities.

They want to stay. They are willing to relocate to stay. They need to work, and they want to be teachers. They just need an opportunity to demonstrate skills.

Extensive prior experience, resilience

One factor fuelling Canada’s teacher shortage is burnout. Many leave the profession within just a few years, citing overwhelming workloads, lack of support and mental health strain.

Around 25 to 75 per cent of Canadian teachers report experiencing moderate to severe burnout, with high emotional exhaustion affecting up to three quarters of teachers in some provinces.

Against this backdrop, IETs represent a formidable, yet under-tapped, resource. These educators have already demonstrated resilience. Many have taught in environments with class sizes of 50 or more, managed demanding schedules with little institutional support and thrived where resources are scarce.

Learning curve is expected for many teachers

The concern that internationally educated teachers lack Canadian classroom experience is no different from the learning curve faced by novice teachers educated in Canada.

Findings from the 2021-22 British Columbia New Teachers Survey reveal that many new B.C.-trained teachers begin their careers feeling under-prepared for essential aspects of teaching — from managing diverse learning needs to handling workload pressures and classroom complexity.

In contrast, IETs often bring extensive prior experience and resilience.

Fear from employers

The fear — often unspoken — is that recognizing their qualifications would mean lowering standards. But this argument has no validity.

The B.C. Teacher Regulation Branch (TRB) currently grants internationally certified teachers temporary teaching permits, typically valid for three years. But rather than assessing these teachers’ suitability based on demonstrated classroom performance during that period, the TRB requires them to complete multiple additional university courses before obtaining a full B.C. teaching certificate.

The best way to understand existing school systems is to work in them — to teach, to interact with students and colleagues, to participate in the daily life of a school.

By denying internationally trained teachers this route, B.C. undermines its own educational philosophy.

If Canada is serious about addressing the teacher shortage, it must take immediate steps to dismantle credentialing barriers for IETs. Canada cannot afford to let bias stand in the way of solutions. Internationally educated and experienced teachers are not a problem to be fixed — they are part of the solution for a system under strain.

The Conversation

Gloria Ramirez receives funding from The Social Sciences and Research Council of Canada

Victoria Handford and Wei Lin Ang do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

ref. Internationally experienced teachers: An overlooked resource to address teaching shortages – https://theconversation.com/internationally-experienced-teachers-an-overlooked-resource-to-address-teaching-shortages-267171

War of words between China and Japan is fuelling real tension in the Asia-Pacific region

Source: The Conversation – Canada – By Kuan-Wei Chen, Researcher, Air and Space Law, McGill University; Bond University

In a now deleted social media post, the Consul General of the People’s Republic of China to the Japanese city of Osaka recently threatened to “cut off” Japanese Prime Minister Sanae Takaichi’s “filthy head.”

This graphic threat was in response to Takaichi’s suggestion that Japan’s Self-Defense Forces may exercise the right of collective self-defence and become involved in the event of a Chinese attack on Taiwan.

China has called on Takaichi to retract her “erroneous remarks.”

The Chinese outrage is apparently intensifying after Chinese military planes were accused of locking their radar on Japanese fighter jets near the Okinawa islands. China also imposed a ban on Japanese seafood imports.

China’s response has political and nationalistic undertones. China views Taiwan as an “inalienable part” of its territory, a reminder of the “century of humiliation” when the [island was ceded by Imperial China to Japan and became a Japanese colony in 1895].

A matter of history — and law

Even after the Second World War ended, sovereignty over Taiwan was never formally settled. China believes Taiwan must be “reunified” with the motherland, if necessary by force.

The number and intensity of Chinese military drills aimed at intimidating Taiwan have significantly increased in recent years. Chinese leader Xi Jinping has reportedly begun mobilizing the People’s Liberation Army for an invasion of Taiwan by 2027.

Taiwan’s status is complicated under international law. While it has a functioning government, population and defined territory — all necessary elements of statehood — much of the world does not officially recognize Taiwan as a state.

Most countries, including Canada and the United States, engage with Taiwan in a non-official capacity and simply “acknowledge” China’s insistence that Taiwan is part of China.

This respect paid to China is a matter of geopolitics and strategic ambiguity likely due to China’s global economic and political clout, and has little foundation in law.

International resolutions, declarations

China often asserts the 1943 Cairo Declaration as the legal basis for its claim over Taiwan. However, this unsigned media communiqué lacks legal force under international law, something pointed out by British Prime Minister Winston Churchill in 1955.

At the outbreak of the Korean War, U.S. President Harry Truman stated unequivocally that the “determination of the future status of (Taiwan) must await the restoration of security in the Pacific, a peace settlement with Japan or consideration by the United Nations.”

The 1951 Treaty of San Francisco, which ended the war between Japan and the Allied powers, is a legally binding treaty. While Japan renounced “all right, title and claim” to Taiwan, there was no mention of the People’s Republic of China — established only two years earlier — in terms of Taiwanese sovereignty.

The United Nations has never considered, let alone decided upon, the issue of sovereignty over Taiwan. China often cites the UN’s General Assembly Resolution 2758 in 1971 as another legal basis for its assertion of sovereignty over Taiwan. But that resolution only addresses the status of the People’s Republic of China as the legitimate representative of China and makes no mention of Taiwan.

The European Parliament and the parliaments of Australia, the Netherlands, as well as U.S. congress, have openly opposed China’s distortion of the UN resolution and attempts to exert undue influence over international organizations for political ends.

Japan-Taiwan proximity

Takaichi’s remarks are simply a reiteration of the late Japanese Prime Minister Shinzo Abe’s remarks that “a Taiwan emergency is a Japan emergency (台湾有事は日本有事).”

This is no surprise since, at their closest point, Japan and Taiwan are just over 100 kilometres apart. Japan’s deployment of anti-air missiles on the Okinawa prefecture’s Yonaguni Island and long-range anti-ship missiles at the mouth of the Miyako Strait are clearly aimed at countering a potential Chinese offensive.

The site of the largest American Air Force base in East Asia just a 90-minute flight from Taiwan, and is similarly already gearing up for a potential Chinese missile attack amid rising tensions.




Read more:
Why a row over military bases on Okinawa spells trouble for US-Japan relations


Taiwan itself is situated at the crossroads of vital maritime and aviation routes, and manufactures more than 70 per cent of the world’s microchips.

If China opts to blockade or attack Taiwan, it will severely impact the world economy since a fifth of global maritime trade, valued at $2.5 trillion, transits through the Taiwan Strait.

It’s in no one but China’s interests if the Chinese mount an attack, and certainly it’s not the will of the 23 million inhabitants of the independent island nation who enjoy some of the highest levels of political and civil liberties in the world.

The U.S. continues to bolster Taiwan’s defence to deter a Chinese attack since Taiwan’s security is pivotal to America’s strategic standing in the Asia-Pacific region and the world.

Global peace and security

With great power comes great responsibility, and this is true for all states. Threats of invasion, the use of force and non-peaceful means of settling disputes are all prohibited under international law. Undiplomatic rhetoric and distortions of history and the law is also detrimental to peace.

If Taiwan truly is a part of China, then there would be no need for an invasion or threats to “crush” any foreign interference. Through its wolf-warrior diplomacy and shows of force, China is in effect globalizing the Taiwan issue.

As the recent G7 statement states, the international community has “an interest in the preservation of peace and stability across the Taiwan Strait” as China’s military drills and threats of war jeopardize “global security and prosperity.”

In a world beset by conflict in the Middle East and an enduring war in Ukraine, tensions are again heating up in East Asia. Will cooler heads prevail?

The Conversation

Kuan-Wei Chen is the recipient of a Australian Government Research Training Program scholarship.

ref. War of words between China and Japan is fuelling real tension in the Asia-Pacific region – https://theconversation.com/war-of-words-between-china-and-japan-is-fuelling-real-tension-in-the-asia-pacific-region-270434

Gen Z is burning out at work more than any other generation — here’s why and what can be done

Source: The Conversation – Canada – By Nitin Deckha, Lecturer in Justice Studies, Early Childhood Studies, Community and Social Services and Electives, University of Guelph-Humber

Gen Z workers are reporting some of the highest burnout levels ever recorded, with new research suggesting they are buckling under unprecedented levels of stress.

While people of all age levels report burnout, Gen Z and millennials are reporting “peak burnout” at earlier ages. In the United States, a poll of 2,000 adults found that a quarter of Americans are burnt out before they’re 30 years old.

Similarly, a British study measured burnout over an 18-month period after the COVID-19 pandemic and found Gen Z members were reporting burnout levels of 80 per cent. Higher levels of burnout among the Gen Z cohort were also reported by the BBC a few years ago.

Globally, a survey covering 11 countries and more than 13,000 front-line employees and managers reported that Gen Z workers were more likely to feel burnt out (83 per cent) than other employees (75 per cent).

Another international well-being study found that nearly one-quarter of 18- to 24-year-olds were experiencing “unmanageable stress,” with 98 per cent reporting at least one symptom of burnout.

And in Canada, a Canadian Business survey found that 51 per cent of Gen Z respondents felt burnt out — lower than millennials at 55 per cent, but higher than boomers at 29 per cent and Gen X, at 32 per cent.

As a longstanding university educator of Gen Z students, and a father of two of this generation, the levels of Gen Z burnout in today’s workplace are astounding. Rather than dismissing young workers as distracted or too demanding of work-life balance, we might consider that they’re sounding the alarm of what’s broken at work and how we can fix it.


No one’s 20s and 30s look the same. You might be saving for a mortgage or just struggling to pay rent. You could be swiping dating apps, or trying to understand childcare. No matter your current challenges, our Quarter Life series has articles to share in the group chat, or just to remind you that you’re not alone.

Read more from Quarter Life:


What burnout really is

Burnout can vary from person to person and across occupations, but researchers generally agree on its core features. It occurs when there is conflict between what a worker expects from their job and what the job actually demands.

That mismatch can take many forms: ambiguous job tasks, an overload of tasks or not having enough resources or the skills needed to respond to a role’s demands.

In short, burnout is more likely to occur when there’s a growing mismatch between one’s expectations of work and its actual realities. Younger workers, women and employees with less seniority are consistently at higher risk of burnout.

Burnout typically progresses across three dimensions. While fatigue is often the first noticeable symptom of burnout, the second is cynicism or depersonalization, which leads to alienation and detachment to one’s work. This detachment leads to the third dimension of burnout: a declining sense of personal accomplishment or self-efficacy.

Why Gen Z is especially vulnerable to burnout

Several forces converge to make Gen Z particularly susceptible to burnout. First, many Gen Z entered the workforce during and after the COVID-19 pandemic.

It was a time of profound upheaval, social isolation and changing work protocols and demands. These conditions disrupted the informal learning that typically happens through everyday interactions with colleagues that were hard to replicate in a remote workforce.

Second, broader economic pressures have intensified. As American economist Pavlina Tcherneva argues, the “death of the social contract and the enshittification of jobs” — the expectation that a university education would result in a well-paying job — have left many young people navigating a far more precarious landscape.

The intensification of economic disruption, widening inequality, increasing costs of housing and living and the rise of precarious employment have put greater financial pressures on this generation.

A third factor is the restructuring of work that is taking place under artificial intelligence. As workplace strategist Ann Kowal Smith wrote in a recent Forbes article, Gen Z is the first generation to enter a labour market defined by a “new architecture of work: hybrid schedules that fragment connection, automation that strips away context and leaders too busy to model judgment.”

What can be done?

If you’re reading this and feeling burnt out, the first thing to know is that you’re not overreacting and you’re not alone. The good news is, there are ways to recover.

One of burnout’s most overlooked antidotes is combating the alienation and isolation it produces. The best way to do this is by building connection and relation to others, starting with work colleagues. This could be as simple as checking in with a teammate after a meeting or setting up a weekly coffee with a colleague.

In addition, it’s important to give up on the idea that excessive work is better work. Set boundaries at work by blocking out time in your calendar and clearly signalling your availability to colleagues.




Read more:
Managers can help their Gen Z employees unlock the power of meaningful work − here’s how


But individual coping strategies can only go so far. The more fundamental solutions must come from workplaces themselves. Employers need to offer more flexible work arrangements, including wellness and mental health supports. Leaders and managers should communicate job expectations clearly, and workplaces should have policies to proactively review and redistribute excessive workloads.

Kowal Smith has also suggested building a new “architecture of learning” in the workplace that includes mentorship, provides feedback loops and rewards curiosity and agility.

Taken together, these workplace transformation efforts could humanize the workplace, lessen burnout and improve engagement, even at a time of encroaching AI. A workplace that works better for Gen Z ultimately works better for all of us.

The Conversation

Nitin Deckha is a member of the Institute for Performance and Learning and the Canadian Community of Corporate Educators.

ref. Gen Z is burning out at work more than any other generation — here’s why and what can be done – https://theconversation.com/gen-z-is-burning-out-at-work-more-than-any-other-generation-heres-why-and-what-can-be-done-270237

Immigrant women care workers keep Ontario’s home care afloat under exploitative conditions

Source: The Conversation – Canada – By Naomi Lightman, Associate Professor of Sociology, Toronto Metropolitan University

Despite recent provincial investments, Ontario’s home-care system is still in crisis. Underfunding, rationed care and ideological preferences for privatization of services undermine dignified aging and care for those in need of support at home.

At the same time, home-care providers, who are disproportionately racialized immigrant women, experience precarious, exploitative and sometimes dangerous working conditions.

My newly released research report, entitled “Caring about Care Workers: Centring Immigrant Women Personal Support Workers in Toronto’s Home Care Sector,” is a collaboration with Social Planning Toronto(SPT), a non-profit, community-based agency. In it, we highlight the concerns and preferences of these undervalued workers.

Our report presents data from interviews with 25 immigrant women working as personal support workers (PSWs) in home care in the City of Toronto. Our conversations, conducted between 2023 and 2025, focused on employment conditions and workplace safety, the critical need for systems change and the possibilities for building PSW collective power.

A vital service held together by precarious labour

Home care provides crucial supports to seniors who want to live in their own homes longer, facilitates the autonomy of people with disabilities and aids in the recovery of individuals following a hospital stay.

Their work both supports widespread client preferences to “age in place” and reduces pressure on hospitals and emergency departments. Yet it is routinely neglected and chronically under-resourced.

PSWs provide the majority of home care services. In 2022, an estimated 28,854 individuals were employed as PSWs in the home-care sector in Ontario. Home-care PSWs collectively provided 36.7 million hours of care to Ontario residents in 2023-24 through the provincially funded system.

Immigrant and racialized women comprise the majority of home care PSWs in the Greater Toronto Area. Home-care PSW labour is characterized by low wages, lack of employment benefits, health and safety risks and unique challenges associated with working alone in private homes.

Among PSWs in Ontario, those working in the home and community care sector have the lowest average wage, making about 21 per cent less on average than PSWs working in hospitals and 17 per cent less than those in long-term care. Inadequate provincial funding and inequitable and restrictive funding arrangements are the primary drivers that create and exacerbate these unacceptable conditions.

PSWs are absorbing the real cost of care

Our research participants explained how the normal costs associated with providing home care are offloaded onto them in several ways.

First, most PSWs in home care provide personal care to multiple clients each day. Travel between client homes is a requirement of their work. Yet participants shared that they either receive low pay or no pay for travel time between client homes.

One of our participants, Kemi, explained how travel time works in her agency:

“The travel time that we are paid is one hour. If I’m working five hours, that’s six hours I’ll be paid. But the thing is that the travel time amount is not the same as your regular wage… travel time is paid some amount less.”

If it takes more than an hour a day to travel between client homes, Kemi does not receive any compensation for that additional time. Yet this is a reality for her on a regular basis.

Joy, another participant, noted that PSWs in her agency personally pay more than half of their transit costs:

“They give us $1.60 per travel, but the payment we give the TTC is $3.50. I requested the company to make it the same, or at least a free TTC pass for the month. But the employer said it wasn’t appropriate.”

At the same time, many PSWs have long gaps of unpaid time between client visits during their workday. These gaps in their workday result in a full-time shift but only part-time compensation, with many getting paid for only a few hours each day. The result is full time work for a part-time wage.

In addition, participants noted that PSWs can have their work hours and income reduced if their caseload is reduced. This occurs when a client dies, moves, enters hospital or long-term care, switches home care providers or no longer requires services.

Ann-Marie described the precariousness of working in home care:

“You know why the hours are not guaranteed? For instance, I have eight clients, and out of eight clients, I have three clients that passed away. That’s all my hours reduced until they able to find another client to fit into my schedule.”

Reform must start with fair working conditions

Our report provides detailed policy recommendations targeted to both levels of government, home-care service provider organizations, unions and the community sector.

In particular, we advocate for the creation of a comprehensive public non-profit home-care system where home care workers, Ontario residents receiving care and their families play a central role. Rather than continuing with a fee-for-service model, we recommend adopting a grant-based funding model to better support the full cost of care provision.

We also advocate for developing employment standards for home care PSWs and improvement of public transparency and accountability in home care through data collection and analysis, along with regular public reporting and independent research. And, finally, rather than continuing to allow large home-care companies to extract millions in profit, we want every public dollar to support high-quality care and good working conditions for home care workers.

For the good of everyone in Ontario, it’s essential that the provincial government take bold action to reform the home-care system. The very least we can do for these essential and valuable workers is to ensure fair compensation, guaranteed work hours and good working conditions.

The Conversation

Naomi Lightman receives funding from the Social Science and Humanities Research Counsel of Canada (Insight Grant number 435-2021-0486).

ref. Immigrant women care workers keep Ontario’s home care afloat under exploitative conditions – https://theconversation.com/immigrant-women-care-workers-keep-ontarios-home-care-afloat-under-exploitative-conditions-270007

Aging bridges are crumbling. Here’s how new technologies can help detect danger earlier

Source: The Conversation – Canada – By Amirreza Torabizadeh, PhD candidate, Civil Engineering, Concordia University

New signs of deterioration recently discovered on the Île-aux-Tourtes Bridge in Montréal have spurred the Québec government to reinforce beams and install shoring just to keep the structure open.

The bridge carries about 87,000 vehicles a day, yet requires constant monitoring and emergency repairs to ensure its safety.

This is a reminder of how aging concrete can deteriorate and cause safety problems.

Canada has thousands of concrete bridges like Île-aux-Tourtes that are reaching or exceeding their intended lifespans. As these structures age, they become more prone to deterioration, much of it happening slowly and out of sight.

Detecting danger earlier

Our research focuses on the modelling of concrete structures that might deteriorate due to environmental stresses and aging. Our goal is to determine how long a structure remains safe and, if necessary, what retrofitting strategies are applicable.

To fully understand these risks, researchers can make use of the most recent technological advances such as drone imaging, AI-assisted defect detection and non-destructive testing to collect regular and reliable data about a structure’s condition.

Combining these technologies with advanced computer modelling techniques could move Canada towards a system that detects danger earlier, prevents costly failures and supports smarter decisions about repair and retrofit strategies.

Across Canada, many of the concrete bridges built between the 1960s and 1980s are now nearing the end of their service life. The 2019 Canadian Infrastructure Report Card found that nearly 40 per cent of the country’s roads and bridges were in fair, poor or very poor condition, showing how widespread the problem has become.




Read more:
Concrete with a human touch: Can we make infrastructure that repairs itself?


Due to environmental conditions in Canada, freeze-thaw cycles, road salt and moisture serve to accelerate cracking and surface deterioration. Research on concrete durability in cold climates has documented how these mechanisms gradually reduce structural performance.

Climate change is also intensifying heavy rainfall, temperature swings and loading conditions, all of which place additional stress on aging structures. In Western Canada, seismic vulnerability adds another layer of risk for older concrete bridges.

Together, these factors contribute to growing maintenance backlogs and a pattern where deterioration is often addressed only after it becomes visible or disruptive.

Old inspection models are inefficient

Traditional bridge inspections performed by rope access teams — trained professionals who use ropes and specialized gear to work at height on complex structures like bridges — often require lane closures, disrupt traffic and are expensive.

As a result, these inspections are infrequent, allowing damage to develop unnoticed between inspection cycles. The information collected during these inspections is often inconsistent, since different crews may use different ways of recording defects.

When problems are found late, repairs require more lane closures, detours and long work periods. These shutdowns also carry economic costs because downtime affects businesses, commuters and essential services. Earlier detection would let cities plan smaller repairs and use strengthening methods that cause less disruption.

Cost, time and accuracy are the three main factors engineers must balance when assessing aging infrastructure. Our research focuses on accurately predicting the structural risks by modelling how concrete deteriorates over time by considering the occurrence of cracks and environmental stresses.

But even the best model relies on the sufficiency of the collected field information and how much it represents the current state of the structure. To predict the behaviour of a bridge accurately, data must be precise, consistent and updated regularly, something that traditional inspections rarely provide.

How tech can help

New technological advancements on data science and observation techniques are now changing this landscape.

Drones can capture high-resolution images of cracks and surface damage in minutes, without lane closures or heavy equipment. AI systems can scan these images and highlight subtle patterns that might go unnoticed in a manual survey. Other non-destructive testing methods, like radar or ultrasonic scanning, can detect hidden problems beneath the surface.

When these technologies are combined with advanced computer modelling, civil engineers get a much clearer picture of the state of a structure. This early and accurate understanding helps them plan repairs that are faster and less disruptive. It also reduces downtime — the closures and delays that can create economic costs for businesses and commuters.




Read more:
After the Baltimore bridge collapse, we need clear-eyed assessments of the risks to key infrastructure


With better information, communities can choose repair and retrofit solutions that are more efficient and better timed.

Canada cannot rely on infrequent inspections and emergency repairs to manage its aging bridges. By combining better models with more consistent and automated data collection, engineers can detect problems earlier and avoid the large disruptions that come with last-minute closures.

These tools will not replace engineers, but they will give decision-makers clearer information and more time to plan. Investing in these modern approaches now can help keep our bridges safer, our cities moving and our communities better protected in the years ahead.

The Conversation

Emre Erkmen receives funding from Natural Sciences and Engineering Research Council of Canada.

Amirreza Torabizadeh does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

ref. Aging bridges are crumbling. Here’s how new technologies can help detect danger earlier – https://theconversation.com/aging-bridges-are-crumbling-heres-how-new-technologies-can-help-detect-danger-earlier-270845

Concrete with a human touch: Can we make infrastructure that repairs itself?

Source: The Conversation – Canada – By Mouna Reda, Post doctorate fellow, Department of Civil Engineering, McMaster University

As winter approaches, Canada’s roads, bridges, sidewalks and buildings are facing a familiar problem: cracks caused by large temperature swings. These cracks weaken infrastructure and cost millions to repair every year.

But what if concrete could heal itself like human skin, keeping our structures, roads and bridges strong and saving millions of dollars?

Concrete is the most widely used construction material, known for its durability and low maintenance. Yet it’s still susceptible to cracking.




Read more:
Aging bridges are crumbling. Here’s how new technologies can help detect danger earlier


Concrete is made by mixing cement, water, aggregate and other chemicals used to enhance its properties. As cement reacts with water, it forms a paste that binds everything together.

During this process, changes in volume, improper placement and finishing, and later environmental factors can create cracks. These cracks allow water, other liquids, gases and harmful chemicals to penetrate the concrete, compromising its strength over time.

This challenge has led researchers to eagerly explore what can be done to heal these cracks. In our research, we are researching how self-healing concrete can make infrastructure more durable.

Self-healing concrete

a cracked concrete slab on pillars below an elevated roadway
Cracked concrete under the Spadina Avenue exit ramp on Toronto’s Gardiner Expressway.
(Sylvia Mihaljevic)

When our skin is cut, it’s able to heal on its own. Inspired by this, researchers started re-imagining concrete with similar abilities.

Traditional concrete is able to mend small cracks when water triggers leftover cement in a process known as autogenous healing. This process, however, is very slow and limited to narrow cracks. Since concrete is man-made, it has limited ability to “self-heal” without a little extra help. This led researchers to develop what is called autonomous healing.

Autonomous healing mimics nature by adding special materials like minerals, polymers, micro-organisms or other healing agents into concrete. These materials react chemically or physically with concrete to fill the cracks.

The first modern concept of self-healing concrete was introduced by American researcher Carolyn M. Dry in the early 1990s. In 2006, Dutch microbiologist Hendrik M. Jonkers developed a special concrete that uses bacteria to heal cracks.

Later, Jonkers and civil engineer Erik Schlangen gained attention with “bio-concrete” that incorporates bacteria in spore form. When moisture enters a crack, the spores activate and produce calcium carbonate, one of the most suitable fillers for concrete.

This process, called microbiologically induced calcite precipitation, can heal cracks up to one millimetre wide. The process, however, is very slow and depends on the presence of calcium and moisture in concrete, which makes applying it on a large scale challenging.

Beyond bacteria

The limitations of bacteria-based self-healing led researchers to explore chemical-based mechanisms. These healing agents will react with water, air, cement or curing agent to fill in cracks quickly.

Healing agents can work in two ways: some use a single material, like sodium silicate. Others, like dicyclopentadiene, need two materials. For a two-component type, a substance must be added to start the reaction, and both materials must be released at the same time to repair cracks.

This chemical method can repair larger cracks and works faster than the bacteria-based approaches but comes with its own challenges. The biggest question is: How can we ensure the healing agent survives concrete mixing and is only released when a crack forms?

To address this, researchers store the healing agent in protective mediums — either a special network (called a vascular network) or tiny capsules. These storage mediums protect the healing material until a crack forms. When that happens, the capsules or network rupture to release the healing agent and fill the crack.

Vascular networks require an external reservoir to supply the healing agent, which makes them difficult to cast, vulnerable to damage during casting and susceptible to leaks. Because of this, encapsulation has emerged as a promising approach.




Read more:
Thin, bacteria-coated fibers could lead to self-healing concrete that fills in its own cracks


Encapsulation as a potential solution

Encapsulation involves coating the active agent with polymeric shells to create micro-capsules. Despite its promise, this technique still faces hurdles. Researchers use different methods to make and test the capsules, and there is no standardized way to compare results or test efficacy. The bond between the capsule and the surrounding concrete poses additional challenges and needs more investigation.

In our lab at McMaster University, we are researching the optimum geometrical and mechanical properties of capsules that are compatible with the surrounding concrete. The capsules should survive concrete harsh mixing conditions, while still rupture upon cracking.

We’re also developing a standarized test method to evaluate the survival capsule rate during mixing, and another test to evaluate the efficiency of the self-healing concrete system. And we’re investigating the feasibility of incorporating both bacteria- and chemical-based capsules for short- and long-term self-healing.

More research is needed to determine which self-healing method works best —bio-concrete, chemical-based concrete or perhaps a combination of both.

Ultimately, finding ways to integrate these solutions into infrastructure will benefit communities around the world. Cracks in concrete don’t just look bad; they lead to deterioration over time and costly repairs. That is why developing concrete that resists cracking or heals itself is so important.

The Conversation

Mouna Reda receives funding from Natural Sciences and Engineering Research Council of Canada.

Samir Chidiac receives funding from Natural Sciences and Engineering Research Council of Canada.

ref. Concrete with a human touch: Can we make infrastructure that repairs itself? – https://theconversation.com/concrete-with-a-human-touch-can-we-make-infrastructure-that-repairs-itself-271462