Mechanical Properties of Steel Fiber Geopolymer Concrete under Low Temperature
In order to study the variation of mechanical properties of steel fiber geopolymer concrete(SFGPC)under low temperature,a self-made low temperature environment test device was used to study the failure characteristics and compressive strength and flexural strength of geopolymer concrete at different temperatures(-30,-20,-10,0,20 ℃)and different steel fiber volume content(0%,0.5%,1.0%,1.5%).The microstructure of SFGPC was analyzed by scanning electron microscope(SEM).At the same time,the response surface method(RSM)was used to construct the mechanical property relationship model of SFGPC,which provided a feasible prediction method of compressive strength and flexural strength.The results show that when steel fiber content is 1.5%,the compressive strength and flexural strength of SFGPC at-30 ℃ are 59.8 and 6.6 MPa,respectively,which are 75%and 65%higher than those when steel fiber content is 0%at-30℃,and 41%and 144%higher than those when steel fiber content is 1.5%at 20 ℃,respectively.With the increase of steel fiber content,the internal adhesion and adsorption capacity of SFGPC enhance,and the mechanical properties are improved.The prediction models of compressive strength and flexural strength of SFGPC are obtained by RSM,and the relative errors between the predicted values and the tested values are less than 5.7%and 8.0%,respectively.
steel fibergeopolymer concretelow temperature environmentmechanical propertymicromorphology