Performance Research And Engineering Application Of Early Strength And Quick Hardening Portland Cement Based Concrete

Because of its unique performance characteristics,the early strength and fast hardening concrete has been favored in the rapid construction of concrete pavement,bridge,airport runway,military,municipal transportation,port and other rapid construction projects.The preparation method of this kind of concrete is usually obtained by special cement mixed with certain admixture,but the prepared concrete is often unstable at later stage,and the raw material is expensive,which is monopolized by a small number of manufacturers,which is not conducive to the application and promotion.The purpose of this project is to develop a kind of early strength and fast hardening concrete which is easy to control,early strength,long term strength stability and good durability by using conventional raw materials.This paper studies the early strength of rapid hardening portland cement concrete(referred to as the early strength and rapid hardening Portland concrete)is a new rapid hardening portland cement clinker and special composite cement as cementitious materials,and then mixed with a certain amount of superplasticizer and coarse aggregates and water according to a certain proportion,mixing can be obtained early strength rapid hardening Portland concrete.It belongs to the category of new composite materials,using different series of cement composite theory,is a little Bodo strategy,with low quality cement of high performance cement was prepared by a small number of excellent properties of concrete.In this paper,the early strength and quick hardening mechanism,composition ratio and performance of the early strength and fast hardening portland cement concrete are studied:1)Portland cement clinker and the new fast hardened cement compound,the reaction activity of different minerals,water order is different,and the product can generate chemical reaction equilibrium each other affect other minerals.The main hydration products are calcium silicate and calcium silicate hydrate gel,calcium hydroxide,calcium aluminate hydrate and water sulphur calcium aluminate crystal,when mixed with the new fast hardened cement and Portland cement clinker ratio is 0.5,early strength,rapid hardening portland cement mortar performance and mechanical properties are the best.2)Early strength,rapid hardening portland cement is composed of Portland cement clinker,a new fast hardened cement retarder,respectively 62.9%,31.4%and 5.7%,and then to the early strength and rapid hardening portland cement as the base,fine aggregate,coarse aggregate accounted for 100%accounted for 180%,superplasticizer(polycarboxylate superplasticizer)was accounted for 1%.The composition of early strength and rapid hardening Portland concrete,including Portland cement clinker fineness of 300 mesh.3)A new type of fast hardening special cement is composed of sulphoaluminate cement clinker minerals,gypsum,fly ash and reinforced component M,with the ratios of 54%,10%,30%and 6%respectively.4)The experimental research on different water reducing components and dosage collapse influence degree,compressive strength,flexural strength and bond strength of early to rapid hardening Portland concrete,finally in the early 1%incorporation of rapid hardening Portland concrete superplasticizers was the performance of the best.5)We use the fast freeze-thaw cycle test and frost resistance of sulfate wet cycle test study of early strength and rapid hardening Portland concrete sulfate resistance,results indicated that:when the time is 150 times freezing and thawing,the quality loss of early strength and rapid hardening Portland concrete for the highest rate of 1.08%,relative dynamic elastic modulus for a minimum of 78.3%,antifreeze thawing effect is very obvious;when the dry wet cycle 60 times,the mass loss rate of up to 0.8%,sulfate resistance coefficient of 85.2%is the lowest,so good performance of anti sulfate erosion.Finally,in order to test the effect of early strength and fast hardening portland cement concrete in the actual project,the author team applied it to the repair of highway pit,and the effect was very good in the late inspection of the repair.