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Constitutive equations for fresh mortar and fresh concrete provide the characterization of the mixture's flow and the quantification of the rheological properties. This paper presents a constitutive material model for mortar and concrete that builds on previous research. It postulates that ( a) the shear stress is the sum of three components: static interaction between particles, dynamic interaction between particles, and collision of particles; and ( b) the cell is a representative volume of the mixture. For fresh concrete, the effects of particle collisions are negligible due to high concentration, and the equation reduces to the Bingham model. Experimental data reported in the literature was employed to evaluate the predictive capabilities of the constitutive equations. The model results are found to compare very well with the measured experimental data and the difference is within the measurement errors. [ABSTRACT FROM AUTHOR]

Existing buildings consume most of our non-transportation related energy and are a major contributor to the emission of greenhouse gases. Improving their energy efficiency by applying energy conservation measures (ECMs) remains a major challenge. This paper presents computational tools developed to screen office buildings for retrofit and to select specific ECMs for each building. This selection process accounts for climate, occupancy, building operation, heating and cooling systems, distribution systems, envelope properties, building geometry, and cost of ECMs. The tools screen the complete building set for optimal retrofit opportunities. The methodology adopted in developing the computational tools includes characterization of the office building stock into a manageable set of archetypes; simulation of building operation using specific occupancy characteristics and local climate data; development of energy prediction models for lights, equipment, pumps, fans, domestic hot water, chillers, and boilers; and application of present value analysis to evaluate the cost effectiveness of ECMs. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: This paper presents a rational method to characterize the freeze–thaw salt scaling performance of concrete based on capillary suction forces. The testing program included evaluating the concrete’s chemical chloride binding capacity, degree of hydration, total porosity, compressive strength, sorptivity and de-icer salt scaling resistance conducted at both, 28 days and 2 years. Mixtures consisted of paste and concrete containing 0–60% GGBFS as cement replacement, and a water-to-binder ratio of 0.31 or 0.38. The proposed capillary suction model was adapted to include the concrete’s chloride binding capacity, pore characteristics, and age. Results from the capillary suction model are found to correlate with experimentally measured ionic sorption coefficients. Results revealed that the capillary suction depth decreases with increasing percentages of GGBFS due to blocking of capillary pores as a result of the chemical interaction between the saline solution and the binder material. A freeze–thaw salt scaling resistance factor (F/T SSRF) is proposed which accounts for the concrete’s degree of hydration, sorptivity and tensile strength and is shown to correlate with the concrete’s cumulative mass loss tested in accordance with MTO LS-412. Accordingly, the salt scaling performance of concrete containing GGBFS is influenced by the combined effect of the concrete’s pore size distribution of the exposed surface, chloride binding capacity, degree of hydration, and tensile strength. [Copyright &y& Elsevier]