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Reinforced concrete is a commonly used material for constructing basements in low-rise buildings or residential houses in Canada, and as the use of cross-laminated timber (CLT) advances, the door to think of an alternative basement material to offset greenhouse gas emissions associated with reinforced concrete is open. However, the evaluation of CLT durability in below-grade environments, specifically concerning moisture and mould development, remains an unexplored field in research. Hence, this paper aims to analyze CLT's moisture response and mould growth risk in below-grade environments using field and laboratory experiments. A laboratory experiment was carried out to test a waterproofing membrane solution selected to compose the wall assembly in the field experiment. A large-scale experimental CLT basement was built at a cohesive soil site in Edmonton, Canada. The field experiment involved monitoring the relative humidity, temperature, and soil volumetric water content of the CLT panels, which measure 3 m by 6 m in plan and 2 m deep. Data was collected for an extended period from June 2022 to July 2023. The VVT model, developed by Hukka and Viitanen (1999) and updated by Viitanen et al., 2011 to estimate the mould growth level, was used to predict the risk of mould growth. The laboratory experiment showed that the waterproofing membrane is suitable for protection against moisture in a still-water setup. Field experiment results suggested that the primary moisture source was below the basement floor when the floor was finished inadequately. The moisture content of CLT walls was significantly increased by floor flooding and decreased by heating the basement interior. The acceptable mould index of three was surpassed during periods of abundant water below the basement floor due to flood events, showing that the CLT panels were at risk of mould growth development. • CLT use inbasements is in research stage. This paper contains insights for developing future research on this subject. • CLT in basement construction requires robust envelope with waterproofing membranes that perform well below grade. • Elevated moisture levels could pose structural and biological risks to the CLT basement and its occupants. • CLT basement walls take time to dry, and during this period, the walls may be exposed to risky levels of mould growth. [ABSTRACT FROM AUTHOR]

• Sheltered natural carbonation can be similar between different climates. • Huge impact of curing on natural carbonation for very early age (i.e. 1 day) • Impact of curing is negligible for advanced curing age, regardless of cement type. • Strong impact of precipitation on natural carbonation. • The higher the number of rainy days, the lower the carbonation speed. This paper describes a unique international inter-laboratory study on the carbonation resistance of concrete prepared with different supplementary cementing materials. Concrete specimens – from 45 different concrete mixtures – prepared centrally in Lafarge Centre de Recherche (France) were shipped in a sealed condition to 4 other academia research laboratories (located in USA, Canada, India and China). The specimens were exposed to the ambient environments and atmospheric CO2 concentrations in the five locations, including Lafarge Centre de Recherche in France, in both sheltered and unsheltered condition for a period of 5 years. Measurements of carbonation depth were performed at periodic intervals, and the data was analyzed to assess the influence of climatic conditions on the resistance to carbonation. The results indicate that the general trend of carbonation is not much different irrespective of the macroclimate. Further, the number of rainy days seems to have a more significant influence on the progress of carbonation than the total rainfall in the region. [ABSTRACT FROM AUTHOR]

Abstract: Many transportation authorities in the United States and Canada require condition assessments of concrete bridge decks and roadways as part of scheduled rehabilitation and maintenance programs. Nondestructive test (NDT) methods and laboratory studies are commonly used by engineering consultants to perform these evaluations. Amongst typical NDT methods, ground-penetrating radar (GPR) is one of the best suited to accomplish this task. Unfortunately, reported test results are oftentimes ambiguous, due to the current numerical analysis approach to evaluate the data. This paper describes some of the shortcomings of numerical analysis of GPR profiles and it introduces an alternative method developed by the authors. Several examples of actual field investigations are described, where the computer-assisted visual interpretation of GPR profiles was used to validate and eventually improve this new analysis approach. The authors’ project experiences on several structures indicate that mapping defects by visual identification of corrosion-induced anomalies in concrete is a much more accurate way of mapping defects. The results obtained from the field applications suggest that use of the computer-assisted visual interpretation of GPR data is an efficient and reliable approach that can be used by experienced GPR analysts. [Copyright &y& Elsevier]

• 70 Pullout bond tests with GFRP bars in conventional or seawater-mixed concrete. • Detailed comparison of peak bond strength and bond-slip response. • One-way ANOVA tests were conducted to compare the results. • No statistically significant reduction in bond strength using seawater concrete. Portland Cement Concrete (PCC) is the most used construction material worldwide and its use is expected to increase in the future. PCC intensively uses two main natural resources, namely aggregates and fresh water. The concrete industry consumes about 2 billion tons of potable water annually. Due to climate change, rapid population growth, and industrial activity, there is a scarcity of fresh water; by 2025 more than half of the world's population will be living in water-stressed areas. In contrast, there is abundant seawater in the world, which represents about 97.5% of the total Earth's water. However, the incorporation of seawater in PCC is a complex problem because the sulfate ions can affect the microstructure durability and the chloride ions can accelerate reinforcing steel corrosion, which can compromise the structural integrity. Glass Fiber Reinforced Polymer (GFRP) bars may be used as an alternative reinforcing material to avoid corrosion. This paper assesses the bond strength of two types of GFRP bars with either a sand-coating or spiral grooves using a standard pullout test. Control samples were prepared using concrete made with potable water and compared with companion specimens made with seawater. Parallel experimental programs were carried out in Chile and Canada, with a total of 70 test specimens. The results suggest that there is no statistically significant difference in the short-term (28 day) bond strength of GFRP bars in seawater concrete compared to normal concrete. [ABSTRACT FROM AUTHOR]

• Study of mechanical behavior of reinforced rehabilitated bituminous pavements. • Study the influential factors on bond strength at the interface between geosynthetic and asphalt layer. • Design considerations in reinforced pavement structures. Bituminous pavements cover a large part of Canada's roadway network. Traffic and environmental loadings cause distresses and damages in the pavement structure. A traditional approach for pavement rehabilitation is to implement an asphalt overlay on existing deteriorated bituminous pavement at specific times during its service life. However, this approach is somewhat expensive in the long run and not environmentally friendly. On the other hand, several studies indicate that the inclusion of a geosynthetic layer under an asphalt overlay leads to extended pavement service life. Nevertheless, there are still some discrepancies between fields and modeling results. These mainly stem from the fact that the mechanical behavior of reinforced asphalt overlay has not entirely been understood, which results in underestimate or overestimate design solutions. This paper first aims to review different aspects of mechanical interaction between geosynthetic material and asphalt overlay. Afterwards, essential considerations need to be considered in the design procedure to obtain an efficient reinforced-rehabilitated bituminous pavement structure are discussed. [ABSTRACT FROM AUTHOR]