Research On Energy-Saving Block Of Lightweight Aggregate Recycled Concrete

Building energy consumption is a major part of energy consumption structure in the total energy consumption.With the rapid development of economy and the improvement of people's quality of life,building energy consumption is not static,but showing an increasing trend year by year.Taking the road of sustainable development in our country,it is urgent to improve the energy efficiency of building envelope.With the advantages of light weight and good thermal performance,the lightweight aggregate recycled concrete has broad application prospects in the use to the envelope in energy-saving renovation work.The main work and conclusions of this paper are as follows:1.Based on the 100%recycled coarse aggregate replacement ratio,the total volume of coarse and fine aggregates was replaced by polystyrene particles,the substitution rate was 0-50%.In order to study the effect of the replacement ratio of polystyrene particles on the mechanical properties and thermal performance of recycled concrete,the compressive strength and the coefficient of thermal conductivity of 6 groups of recycled concrete was tested by electro-hydraulic servo press and HFM436 thermal conductivity analyzerer.And the proportion of polystyrene particle recycled concrete was optimized.The results showed that the compressive strength,apparent density and thermal conductivity of recycled aggregate concrete decreased with the increase of the substitution rate of polystyrene particles,and the descending speed was increased.The effect of polystyrene particles on the compressive strength of concrete is the largest,on the thermal conductivity is the second,and on the apparent density is the smallest.It showed that the substitution ratio of polystyrene particles is 50%.2.The hole shape of the block is designed,the compressive strength and the temperature rise of 1h indoor temperature rise of the designed hole is simulated with ABAQUS software.The results showed that under the pressure,the stress of the corner of the block and the middle part of the transverse ribs on both sides of the hole bore was relatively large,and the middle part of the block is relatively small.The corner design of rectangular hole can improve the strength of the block.The tensile damage zone is prone to damage in the width direction and transverse and longitudinal rib joints,and the location and the number of the damaged zone are influenced by the number of holes arranged and the number of holes.By increasing the width of the block,or increase the number of rows,the lifting effect of the thermal performance of the block would be limited if the heat transfer of heat in the concrete path can not be increased effectively.By comparing the results of numerical simulation,it was found that QK233 pass block is reasonable.3.The experiment prepared the recycled concrete energy saving building block with optimized mix proportion and pass,tested the compressive strength and calculated it's thermal performance.By using the JTRG-I building palisade structure heat preservation,the thermal performance test of 4 surface block was tested,and the block and painting materials was studied in the influence of the thermal performance of wall.The results showed that the strength of the block can meet the standards of MU5,which is 26%higher than that of ordinary block in theory.The EPS board can meet the requirement of 50%energy saving in the hole.With the mathods of optimizing the mix proportion and pass,inserting the EPS board into the hole,combining with insulation mortar and so on,the wall heat transfer coefficient would be reduced,the wall thermal performance would be improved to meet the standards of 50%or even 65%energy saving.