石粉對機制砂混凝土早期收縮和開裂性能的影響研究

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中圖分類號：TU525 文獻標志碼：A 文章編號：1005-8249（2025）02-0044-06

DOI：10.19860/j.cnki.issn1005-8249.2025.02.008

Abstract：To studytheinfluence of stone powder contentontheearlyshrinkageand cracking performance of manufactured concrete，the working performance，earlyshrinkage，early cracking，compressve strength，andpore distributionof manufacturedsandconcretewithdiffrentstrengthanddiferentcontentsweretested.Thetestresultsshowthattheaddtionof stonepowderisbeneficialtoimprovethewaterretention，ohesiveness，andanti-segregationperformanceofmanufacturedsand concrete but it willincrease theamount of waterreducing agent andearlyshrinkage strain of manufacturedsand concrete.An appropriate amount of stone powder is beneficial toimprovethecrackresistance and compressivestrength of manufacturedsand concrete，butexcesivestone powder willead tothedecreaseofcrackresistanceandcompressive strength.The stonepowder content in manufactured sand can be relaxed to 20 % for C3O concrete，and the content of stone powder should be controlled within 10 % for the C5O concrete.The optimum value of stone powder content in manufactured sand for concrete should be determinedincombinationwithengineringenvironmentandpracticaluse，which ismoreconducivetotheexpansionaplication of manufactured sand concrete in areas with poor sand resoures.

Key words： manufactured sand concrete； stone powder content；volume stability；microstructure

0 引言

近年來，為保護生態(tài)環(huán)境和實現(xiàn)可持續(xù)發(fā)展戰(zhàn)略，禁采、限采天然砂的相關規(guī)定相繼出臺，這就導致作為混凝土主要原材料之一的河砂嚴重短缺，機制砂的市場需求出現(xiàn)急劇增長[1-2]。（剩余6724字）