矿渣集料混凝土耐热性的试验

为综合利用工业废渣,以高炉矿渣为粗细集料配制混凝土,于110℃烘干24 h后,在极限耐热温度分别为300、500、700℃下恒温3 h,研究砂率、粗集料最大粒径、水灰比和水泥用量对矿渣集料混凝土耐热性的影响。结果表明:混凝土在300℃的相对耐压强度大于100%;500℃的相对耐压强度为57%~86%;700℃的相对耐压强度为22%~58%。增大砂率、减小粗集料最大粒径、降低水灰比、减少水泥用量,有利于提高混凝土的耐热性;用矿渣集料完全能配制500℃耐热混凝土。

EXPERIMENT ON THERMO-STABILITY OF SLAG-BASED AGGREGATE CONCRETE

In order to comprehensively utilize the industrial waste residue,a concrete was made of a blast-furnace slag taken as coarse and fine aggregate.After 24 h oven drying at 110 ℃,the concrete was treated for 3 h under constant temperatures of 300,500 and 700 ℃ respectively.The study was conducted to measure the impacts of sand percentage(SP),maximum particle size of coarse aggregate,water-cement ratio and cement quantity,on the thermo-stability of slag-based aggregate concrete.The result indicates: at 300 ℃ the relative compression strength(RCS) is above 100%,at 500 ℃,the RCS is between 57%～86%,at 700 ℃,the RCS is between 22%～58%.More SP value,smaller maximum particle size of coarse aggregate,lower water-cement ratio and the less cement quantity are beneficial to enhance the thermo-stability of the concrete;with slag-based aggregate,a concrete can be made with thermo resistance at 500 ℃.