材料期刊网

以 H2 O2溶液(质量浓度30％)为发泡剂,粗、细膨胀珍珠岩颗粒为轻集料和发泡剂载体,明胶为稳泡剂,采用将加载发泡剂的载体拌入轻集料混凝土的水泥浆中原位化学发泡的方法,制备出了系列轻混凝土试样,并对其性能进行了系统表征.结果表明,原位发泡轻混凝土中外加1．5％(质量分数)胶凝材料量的稳泡剂后,对气泡有较为理想的稳泡作用,可获得均匀分布的细小气泡(气泡直径0．5~1 mm).原位发泡轻混凝土的体积密度随发泡剂量增加而降低,随稳泡剂量的增加而增大.当稳泡剂为胶凝材料量的1．5％(质量分数)时,原位发泡轻混凝土试样的抗压强度和导热系数均随着发泡剂量的增加而降低.其中,发泡剂量为胶凝材料量1．4％(质量分数)试样的28 d抗压强度为21 MPa,体积密度为940 kg/m3,比不发泡试样的强质比提高了14％,导热系数降低了13％.

The lightweight concrete (LC)specimens were prepared using the method of chemical foaming in situ. In the foaming process,the H2 O2 was used as foaming agent,the coarser and fine expanded perlites were used as lightweight aggregate and as carrier for H2 O2 respectively,and the gelatin was used as foam stabilizer.The foaming reaction of H2 O2 was taken place after it was being charged into carriers and the charged carriers were mixed into the mortar previously.The mortar was enclosed by the lightweight aggregates in fresh concrete.The properties of the resulting LC specimens were characterized systemically.It was found that the adding amount of 1.5wt% foam stabilizer had the promising stabilization for the foam formed in situ,which resulted in the bubbles with 0.5-1 mm diameter in homogeneous distribution.The bulk densities (BD)of resulting LC speci-mens were decreased with the increasing of the adding amount of foaming agent,and increased with the adding amount of foam stabilizer.For the resulting LC specimens with foam stabilizer amount of 1.5wt%,their 28 d compressive strengths (CS)and thermal conducting coefficients (TCC)were decreased with the increase of the amount of foaming agent.Among them,the resulting LC specimen with foaming agent of 1.4wt% had the 28 d CS of 21 MPa and the BD of 940 kg/m3 .As compared with that of the resulting LC specimen without foaming agent,its specific strength value was improved by 14% and its TCC was decreased by 13%,respectively.