EXPERIMENT DESIGN TO EVALUATE THE EFFECT OF MIXTURE PARAMETERS ON RHEOLOGICAL PROPERTIES OF SELF-CONSOLIDATING CONCRETE EQUIVALENT MORTAR

摘要

Providing the proper rheological properties of the mortar phase of self-consolidating concrete(SCC)is crucial to the control of deformability and stability of the suspension.This can be achieved by tailoring the mix design parameters,including water-to-powder ratio(W/P),dosage and type of chemical admixtures,and type and content of supplementary cementitious materials(SCM).Given the number of mixture parameters and opposing effect of different parameters on flow properties,optimization can necessitate several trial batches to ensure suitable fluidity,stability,and mechanical properties.The study presented here was undertaken to highlight the effect of high-range water-reducer(HRWR)dosage,limestone filler(LF)and fly ash(FA)contents,and W/P on the rheological properties of highly-flowable mortar that can be used to design SCC using experiment design approach.The established models can be used to develop mixture-proportioning guidelines given the relative significance of each independent parameter on the plastic properties of the mixture.Derived statistical models indicate that the measured properties of mortar are highly influenced by the level of replacement content of FA and LF,W/P,HRWR and several coupled effects of these parameters.The partial replacement of cement by FA and LF is shown to enhance fluidity for mixtures with fixed W/P and HRWR content.On the other hand,for a given fluidity level,the use of FA and LF results in reduction in required W/P and HRWR demand,hence providing greater mechanical properties and durability of the hardened system.