矿渣-粉煤灰基地质聚合物混凝土的基本性能研究

Study on the basic properties of slag and fly ash based geopolymeric concrete

地质聚合物混凝土是一种新型混凝土类材料。为了研究地质聚合物混凝土的基本性能,以矿渣、粉煤灰为原料,以硅酸钠和氢氧化钠为激发剂,制备了矿渣-粉煤灰基地质聚合物混凝土,测试了不同配合比下矿渣-粉煤灰基地质聚合物混凝土的坍落度以及7、14 d和28 d的抗压强度,分析了水胶比对和易性与抗压强度的影响,探讨了抗压强度的增长规律。结果表明:制备的矿渣-粉煤灰基地质聚合物混凝土具有较高的抗压强度和良好的和易性,凝结硬化快,强度特性稳定;当水胶比为0.26,砂率为0.40,氢氧化钠和硅酸钠的质量比为0.29,碱溶液的浓度为56%时,矿渣-粉煤灰基地质聚合物混凝土的坍落度为110 mm,标准养护条件下7、14 d和28 d龄期的抗压强度分别达到40.4、50.3 MPa和60.20 MPa;随着水胶比的增大,和易性不断增强,抗压强度先增加,后减小;随着养护龄期的延长,抗压强度不断增长,但增速降低。

Geopolymeric concrete is a new kind of concrete.ln this paper,in order to study the basic properties,the slag and fly ash based geopolymeric concrete specimens was prepared by sodium silicate and sodium hydroxide alkali-activated slag and fly ash.The slump and compressive strength in 7,14 d and 28 d under different raw material proportion were tested.The effect of water to binder ratio on the workability and compressive strength was analyzed,the increase rule of the compressive strength was discussed.The result indicated that slag and fly ash based geopolymeric concrete has high compressive strength and good workability,the strength increases fast steadily;As the water to binder ratio is 0.26, sand rate is 0.40, the NaOH to sodium silicate ratio is 0.29, the NaOH and sodium silicate concentration in the solution is 56%,the slump is 110mm,the compressive strength in 7,14 d and 28 d under criteria curing regime can reach 40.4,50.3 MPa and 60.20 MPa respectively;with the water to binder ratio increasing, the workability improves, the compressive strength increases first, but reduced then;with the cure time becoming longer, the increasing rate of compressive strength becomes slower.