Concretes and mortars are subjected to several kinds of shrinkage strains which represent the volumic variations resulting from the cement hydration and are governed by various physical and chemical aspects. The use of polyethylene terephthalate PET plastic wastes which are available in quantity and within low cost in our country yields a very important economic and environmental impact in the construction industry. Thus, we are interested to investigate the effect of PET volumetric additive amounts for cement substituting and for the behavior of the total, drying and autogenous shrinkage. Comparison study of obtained experimental results with codale prediction models were performed according to Eurocode 2 (EC2) in order to analyze the evolution of shrinkage strain with PET-mortar composite ages and for several rates of PET waste additions. According to obtained results, PET additions acts to reduce shrinkage strains of PET-mortar composites which promote the use of these modified mortar Eco-materials in the field of construction industry.
Keywords
In Algeria, the calcined dam's mud is a local renewable waste that proved its use as a supplementary cementitious material (SCMs) with similar mechanical performances and better resistance to several physical and chemical attacks than Portland cement. In the same context, the main objective of the work is to evaluate the effect of this calcined mud on thermal conductivity, which was never tested. To concretize this goal, one mortar based on control cement (CEMI) and three others based on modified cement by replacing CEMI by 10% to 30% Wt rates with the calcined mud of Chorfa dam have been prepared and cured before being put to the test procedure. Compressive strength, apparent density, water absorption after immersion, and thermal conductivity at three degrees of saturation state (saturated, outdoors, and dried state) were tested. The results show that using 10% to 20% replacement rate is characterized by good free lime and calcium hydroxide consumption that produces C-S-H gel, fills pores, decreases porosity, and increases density. The thermal conductivity of mortars based on the calcined mud in all states was lower compared than the control mortar, at saturated state by 16.28%, 17.83%, and 18.60% for the mortars 10%, 20%, and 30% (of cement replacement) respectively, at outdoors state by 5.5%, 4%, and 17.5% and dry state with 8.39%, 20.65%, and 38.07%. 10% to 20% mud replacement is beneficial for use in masonry and plastering wall applications of a building's envelope. 30% replacement rate can be developed and used in environments with minimal class expositions.
Our work aims to studying the addition of the natural pozzolan located in Beni Saf (Algeria) at non-destructive testing for the evaluation of pozzolan mortar reinforced to corrosion. We chose to study this natural addition because of its low cost and its pozzolanic reactivity. To do this, we have carried out tests on mortars made to Portland cement CEM I 42,5 N and substituted by weight based percentages of different natural pozzolan (10%, 20% and 30%). We have measured the corrosion potential and the corrosion speed of different deadlines. The results indicated that is it possible to highlight the beneficial effect of this addition. The analysis of achievements shows that the addition of the pozzolan in optimal quantities has the following advantages: protection of reinforcement against corrosion and increase the resistance against the sulfate attack (5% Na2SO4).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.