Experimental Research And Analysis Of The Light Wall Materials On Thermal Insulation Structure

The energy consumption of building envelope is the main cause of building energy efficiency, and the performance of the building envelope directly determines whether the heat energy can be effectively used in the building. Therefore, the thermal insulation performance of the material is the key to achieve building energy efficiency. Through the theoretical analysis and the indoor test of different lengths and different dosage of polypropylene fiber and ceramic sand with different substituted rate instead of the ordinary sand lightweight material mechanical properties of concrete, the apparent density and thermal insulation properties.(1) When adding polypropylene fiber in a certain fiber length, the compressive strength, splitting tensile strength and flexural strength of lightweight concrete present a first increase then decrease change rule with the fiber content increasing. Polypropylene fiber in length of 6 mm demonstrates an obviously improvement effect for compressive strength and splitting tensile strength, which are increased by 6.0% and 20.0% respectively. While polypropylene fiber in length of 17 mm demonstrates an obviously improvement effect for fiexural strength, which are increased by 14.2%. Both compressive strength and splitting tensile strength present a first decrease then increase change rule with fiber length increasing, and polypropylene fiber in length of 6 mm or 17 mm show a good reinforcing effect. While fiexural strength increases with fiber length increasing, but the increse amplitude is small.(2) Hybid polypropylene fiber in vaious fiber length demonstrates an evident improvement effect in splitting tensile strength of lightweight concrete. When the content of polypropylene fiber in length of 6 mm,11 mm and 17 mm are all 0.1%, an remarkable improvement effect for splitting tensile strength is shown, which are increased by 21.5%.(3) The failure modes of plain lightweight concrete in compression experiment, splitting tensile experiment and flexural experiment show a brittle failure characteristics, while the failure mode of fiber reinforced lightweight concrete show a plastic failure characteristics, which indicates a good bridging traction action of polypropylene fiber.(4) With substitution rate of ceramsite sand to ordinary sand increasing, the compressive strength, splitting tensile strength and apparent density of lightweight concrete present a linear decrease tendency. When substitution rate is 80%, the cracks in compression experiment are parallel to each other, which is similar with the ordinary concrete specimen with lube on both ends in load direction.(5) Polypropylene fiber have a little influence on the apparent density and thermal conductivity of lightweight concrete. When abmient temperature is high or big tempertaure differece exists, big thermal conductivity presents.(6) Optimal combination of ceramsite sand and polypropylene fiber in lightweight concrete is 40% substitution rate and 0.1% content for polypropylene fiber in length of 6mm,11 mm and 17 mm each.