Key Engineering Materials Vol. 666

Abstract: The construction industry is a major energy consuming sector. Seen in the global context of increasing resource efficiency, this necessitates a comprehensive review of the embodied energy of the materials used in construction It has been a commonly observed phenomenon that the energy demand in earlier days was comparatively lesser compared to the present scenario. This paper attempts a comparative analysis of embodied energy of single family residences in Kerala, constructed using traditional methods as well as modern techniques by choosing one specific example for study from both the categories.

Abstract: Concrete is composed of a liquid phase (paste) and of a solid phase (aggregates with fixed gravel/sand ratio), the concrete self-compacting properties come necessarily from those of the paste. The present research is the continuity of a first phase of the testing already conducted, which resulted in obtaining an optimal self-compacting cement paste composition. This paste will be used to prepare a self-compacting concrete (SCC), while passing from the scale of the cement paste to that of the concrete, by injecting wet aggregate to the self-compacting paste. The excess paste theory was used to determine the thickness of the paste coating each aggregate with a given diameter of constituting granular skeleton, then generalized for the determination of the quantity of total paste allowing the flow of the concrete by decreasing frictions between the grains of its granular skeleton. This approach was also experimentally validated. The influence of the granular distribution was minimized by the use of the approach based on the determination of the average diameter of the aggregates. This required the determination of a homothetic factor “K” similar for all concretes with different aggregate grading. Formulation of a self-compacting concrete passes initially by the determination of a sufficient quantity of paste allowing its flow without frictions between its aggregates and to balance the mixture by the quantity of water retained by the aggregates. The self-compacting concrete characteristics would come from those of the cement paste which composes it.