三元地质聚合物力学性能和微观结构研究

Research on the mechanical properties and microstructure of ternary geological polymers

使用粉煤灰、矿粉和不锈钢渣粉制备三元地质聚合物,开展了原料配比、碱激发剂含量以及水玻璃模数对地质聚合物力学性能的影响,并利用SEM、EDS和XRD对试样进行了微观结构和物相成分分析。结果表明:在粉煤灰基础上,矿粉和不锈钢渣粉的添加降低了惰性晶体峰的强度,提高了试样的Si/Al,宏观表现为力学性能提高,当粉煤灰、矿粉和不锈钢渣粉占比为80%、60%、40%时,试样28 d抗压强度达到70.1 MPa;三元地质聚合物的抗压强度随着碱激发剂含量和模数的增加先提高后降低,同时抗压强度的提高会导致抗折强度降低试样变脆,且易出现收缩裂纹;与水泥相比,三元地质聚合物晶相主要为原料中未反应的惰性物质以及新生成的钠沸石和钙沸石,非晶相主要为C-S-H和N(C)-A-S-H共存产物。

A ternary geopolymer was prepared using fly ash,blast furnace slag powder,and stainless steel slag powder.The effects of raw material ratio,alkali activator content,and water glass modulus on the mechanical properties of the geopolymer were investigated,and the microstructure and phase composition of the samples were analyzed using SEM,EDS,and XRD.The results showed that the addition of blast furnace slag powder and stainless steel slag powder reduces the strength of the inert crystal peak,improves the Si/Al of the sample,and macroscopically improves the mechanical properties,and when the addition ratios of fly ash,mineral powder,and stainless steel slag powder are 80%,60%,and 40%,the compressive strength of the sample after 28 days reaches 70.1 MPa.The compressive strength of ternary geological polymers increases first and then decreases with the increase of alkali activator content and modulus.At the same time,the increase of compressive strength will lead to a decrease in the flexural strength of the sample,making it brittle and prone to shrinkage cracks.Compared with cement,the crystalline phase of ternary geopolymer mainly consists of unreacted inert substances in the raw materials,as well as newly generated sodium zeolite and calcium zeolite,while the amorphous phase mainly consists of coexisting products of C-S-H and N(C)-A-S-H.