Effects of microfine aggregate in manufactured sand on bleeding and plastic shrinkage cracking of concrete  

作　　者：Branavan ARULMOLY Chaminda KONTHESINGHA Anura NANAYAKKARA 

机构地区：[1]Department of Civil Engineering,University of Sri Jayewardenepura,Mount Lavinia 10370,Sri Lanka [2]Department of Civil Engineering,University of Moratuwa,Moratuwa 10400,Sri Lanka

出　　处：《Frontiers of Structural and Civil Engineering》2022年第11期1453-1473,共21页结构与土木工程前沿（英文版）

基　　金：The authors are grateful to INSEE Siam City,Sri Lanka for providing the necessary binding materials to conduct this study.Furthermore,the authors wish to thank all technical staffs of the Department of Civil Engineering,University of Sri Jayewardenepura for their support on the experimental work.

摘　　要：Construction industries have started to utilize manufactured sand(MS)as an effective alternative for river sand in concrete.High-grade parent rocks are crushed to obtain MS,which also produces a considerable amount of microfine aggregate(MFA).The higher percentage of MFA could lead to both positive and negative effects on the performance of cement-based mixes.This research was done to examine the influence of varying MFA levels,specifically 0%,3%,6%,9%,and 12%(by weight)as the partial replacements of MS on bleeding and plastic shrinkage cracking of concrete.In addition to the varying MFA levels,some concrete mixes also included fly ash(FA)and superplasticizer to investigate the effect of free-water content in the mixes.The bleeding test data were taken as on-site measurements,while the cracks from the plastic shrinkage cracking test were evaluated using an image processing technique.The results concluded that the MFA replacements and the effective water-to-cement ratio have a significant effect on the selected concrete properties.With the increasing replacement levels,cumulative bleeding and crack initiation life gradually decreased,while a progressive increase was observed for crack width,crack length,and crack area.

关 键 词：manufactured sand fresh concrete microfines ADMIXTURES SHRINKAGE CRACKING 

分 类 号：TU528[建筑科学—建筑技术科学]