Research On The Method Of Rapid Improvement Of Early Strength Of Precast Concrete Without Steam Curing

As an important building material,concrete is widely used in modern civil engineering.my country’s concrete technology has developed rapidly in recent decades,but the strength of ordinary concrete grows slowly under conventional curing conditions,and it is difficult to adapt to the requirements of prefabricated components to improve production efficiency and reduce production costs.Therefore,the rapid hardening and early strength of concrete are studied.Technology is of great practical significance.This article is based on the materials commonly used in component factories and the materials commonly used in the market that are conducive to improving the early strength of concrete,such as fast hardening sulphoaluminate cement,ultrafine mineral powder,early strength agents,etc.under standard curing conditions.Admixtures(Kezhijie,Tianjin Hongshi,self-developed KHPC)and cement varieties were tested for comparison,and qualitative tests were conducted for the content of early-strength agent,cement dosage,and fly ash content.Find out the mix ratio that meets the strength requirements in winter,summer,spring and autumn,and then carry out natural maintenance.Test verification is carried out to ensure that the concrete components meet the requirements of early demoulding in winter,summer,spring and autumn.Finally,through engineering example verification and economic analysis,the concrete is adjusted and optimized,and the production and use effects of the developed inflatable plastic film curing shed are analyzed.A method is formulated to quickly increase the early strength of precast component concrete under the condition of no steam curing,and achieve the demoulding strength requirement of precast component within 16 hours.Through the above methods,BBMG,sulphoaluminate cement produced by Shanghai Shun’an Building Materials Co.,Ltd.,self-developed KHPC superplasticizer and Chongqing Jianyan Kezhijie superplasticizer were selected as experimental materials.It is concluded that the water-binder ratio is 0.31 in winter,0.35 in spring and autumn,and 0.37 in summer,the best sand ratio is 45%,and the best fly ash content is 20%.The self-developed KHPC superplasticizer has long side chain and short main chain.The actual water reduction rate is as high as about 35%,which can make the water-binder ratio as low as 0.31,and has good adaptability to Portland cement and sulphoaluminate cement.,The slump protection effect is obvious,and the construction is convenient.A method to quickly improve the early strength of precast concrete in winter,spring,autumn,and summer is obtained,and the overall cost is lower than that of ordinary concrete.