专用矿物掺合料对泡沫混凝土性能的影响研究

Effect of customized mineral admixture on the properties of foamed concrete

利用P·O 42.5R与专用矿物掺合料,在水胶比0.5的条件下,结合物理发泡方法,成功制备了400等级回填用泡沫混凝土,采用扫描电镜与X射线衍射对泡沫混凝土微观结构进行了研究,同时还探讨了掺合料掺量对气孔、抗压强度及收缩的影响。研究表明:专用掺合料掺入导致泡沫混凝土流动度增大,气孔变大,28 d抗压强度先升高后降低;当掺合料取代20%水泥,制备出的泡沫混凝土干密度为390 kg/m 3,28 d抗压强度增长3.5%,为1.5 MPa;28 d收缩降低明显,掺合料取代20%以上,出现微膨胀现象。

Foamed concretes of grade 400 for filling based P·O 42.5 R and customized mineral admixture were prepared by introducing foam into cement paste with w/b ratio of 0.5,the microstructure of foamed concrete was studied by XRD and SEM,and the effect of mineral admixture on pore,compressive strength and shrinkage was also investigated.The results indicate that air-voids sizes increased and the fluidity was improved,when mineral admixture was added into cement paste.The compressive strength at 28 days increased and then decreased.At 20%replacement of cement by mineral admixture,the dry density of foamed concrete was 390 kg/m 3,the compressive strength at 28 days increases by 3.5%and achieve 1.5 MPa,the shrinkage at 28 days decreased.When mineral admixture was more than 20%,expanding of foamed concrete occurred.