Study On Performance Of Low Density High Specific Strength Lightweight Aggregate Porous Concrete And Its Prefabricated Wallboard

With the promotion of building energy-saving work and the improvement of people’s requirements for building functions,in addition to meeting the structural safety functions,the building materials also require functions such as light weight,thermal insulation,sound insulation,noise prevention,anti-shock,fire-retardant and fire-proof.And in actual engineering,cost is even more important factors.Lightweight aggregate porous concrete is a lightweight concrete material based on the design,adding air entraining agent or physical,and adding suitable foam micropores in lightweight aggregate concrete.In this paper,the key technology of high specific strength of lightweight aggregate porous concrete with low cement content is studied by changing the mix proportion parameters,and the thermal performance of partition board made of lightweight aggregate porous concrete is also studied.The relationship among rheological properties of slurry and foam stability and the workability of lightweight aggregate concrete was studied.It provides key parameters for the preparation and quality control of lightweight aggregate porous concrete.The effects of rheological properties（plastic viscosity and yield stress）on foam stability（through volumetric water absorption and wet density characterization）were studied.The relationship between slurry rheology and the workability of lightweight aggregate porous concrete was established.It can be concluded that the best viscosity range of mortar is 7 Pa·s⁸ Pa·s,the loss rate of foam is the smallest,and lightweight aggregate will not float up,and the performance of porous concrete is good.High specific strength lightweight aggregate porous concrete with various density grades was prepared.The maximum specific strength of porous concrete can reach 11.2×10^-3.The effects of silica fume,aggregate varieties and fibers on the strength,density,workability and functionality of concrete were studied.The results show that the addition of silica fume can improve the stability of foam and increase the specific strength of concrete.Compared with sintered lightweight aggregate,the core-shell lightweight non-burnt aggregate has a closer bond with the matrix.The concrete prepared by the core-shell lightweight aggregate has fewer harmful holes,better pore structure,better workability and higher specific strength.The addition of fibers in concrete can significantly improve the shrinkage performance of concrete,increase the flexural strength of concrete,improve the mixing strength,and permeability of concrete.Prefabricated wallboard with light aggregate porous concrete was prepared.The heat transfer coefficient of the wallboard was measured on the spot.Combined with the field test data of the wallboard,the simplified calculation and Ansys simulation analysis of the heat transfer coefficient of the prefabricated wallboard with different holes were carried out.It can be concluded that increasing the hole diameter of the wallboard can improve the thermal insulation performance of the wallboard.The heat transfer coefficient of square holes is less than that of elliptical holes and less than that of circular holes.