Optimization of mix ratio of reservoir sediment foamed concrete based on response surface method

Abstract

[Objective] To improve the high-value utilization of reservoir sediment, reservoir sediment foamed concrete was prepared by taking the water binder ratio, reservoir sediment mixing amount and foam mixing amount as variables. [Methods] The response surface method in the Design-Expert 13.0 software was used to optimize the mix ratio design, analyze the effects of variables on the compressive strength and thermal conductivity of the reservoir sediment foamed concrete. SEM and XRD were used to explore the microstructure of the reservoir sediment foamed concrete. [Results] The results show that the influence of each factor on the 28 d compressive strength of reservoir sediment foamed concrete is in the following order: water binder ratio>foam content >reservoir sediment content, and the thermal conductivity is in the following order: water binder ratio> reservoir sediment content >foam content. With the increase of water binder ratio, the compressive strength increases at first and then decreases, and the thermal conductivity gradually decreases. Increasing foam and reservoir sediment mixing result in a decrease in both compressive strength and thermal conductivity. Porosity showed a negative correlation with thermal conductivity, consistent with an exponential model. [Conclusion] The optimal mix ratio of reservoir sediment foamed concrete is 0.4, 30% of reservoir sediment and 4.2% of foam content, and the 28 d compressive strength of the foamed concrete is 18.19 MPa, and the thermal conductivity is 0.121 4 W/(m·K), apparent density is 701.2 kg/m³. The analysis of microscopic result showed that the internal material of the specimen was tightly bound and the pores were uniformly distributed under the condition that the amount of reservoir sediment was 30%. Reservoir sediment foamed concrete provide a new way for the use of reservoir sediment in the field of construction materials.

Keywords

reservoir sediment / foamed concrete / response surface method / compressive strength / thermal conductivity / influencing factors / water cement ratio / SEM image