Experimental Study On Mechanical Properties, Thermal And Acoustic Insulation Of Ceramsite Cellular Concrete

Ceramsite cellular concrete(CCC)is a new type of inorganic wall insulation material,which has broad application prospects.And it has a series of advantages such as lightweight,thermal insulation and sound insulation.This paper carried out the experimental studies on the basic mechanical properties and thermal performance,the thermal insulation of the composite board and the acoustic insulation of block wall based on the CCC material.Firstly,the basic mechanical properties and thermal properties of CCC were studied,and the relationship between density and various properties was discussed,the quantitative relationship between axial compressive strength,tensile strength,deformation properties and cube compressive strength was analyzed as well.The results show that,under this experimental condition the apparent density of CCC is between 505 kg/m3?1115kg/m3,the axial pressure ratio is 0.65?0.98,the tension and compression is 7%?15%,the bending-compression is 5%?13%,the elastic modulus is 1.38×103?8.4×104MPa,the Poisson's ratio is 0.31?0.18,the thermal conductivity is 0.154?0.34W/(m·K)and the heat storage coefficient is 2.2?4.8W/(m~2·K).And the cube compressive strength,axial compressive strength,splitting tensile strength,flexural strength,elastic modulus,thermal conductivity and heat storage coefficient of CCC increase with the apparent density.The Poisson's ratio of CCC decrease with the apparent density increase.What's more,the mechanical performance of CCC with spherical aggregate is superior to that with the cylindrical ceramsite.In the case of high apparent density,the mechanical properties of CCC with shale ceramsite are better than those with clay ceramsite.Moreover different ceramsite aggregates have little effect on the thermal properties of concrete.Secondly,the heat flow meter method was used to test the average heat transfer coefficient of the composite boards with different CCC thickness.At the same time,the measured values were compared with the theoretical calculation value of heat transfer coefficient,and according to the Design standard for energy efficiency of residential buildings in hot summer and cold winter zone,its heat transfer performance was evaluated.The results show that,the average heat transfer coefficient K of the composite board with thickness of 150 mm and 200 mm were 1.35 W/(m~2·k),0.94 W/(m~2 k),and the thermal inertia D were 3.0 and 3.8,respectively.And they could satisfy the thermal index(K<1.5 W/(m~2·k),D>2.5)of exterior wall of residential building with building shape coefficient<0.40 according to the above standard.And the composite slab with a thickness of 200 mm in the thermal insulation layer also meets the limit of the thermal performance(K<1.0 W/(m~2·k),D>2.5)of exterior wall of a residential building with building shape coefficient>0.40 in the specification.And due to the large thermal inertial value of CCC wall materials,the building is more livable.Meanwhile,the dynamic change law of the heat transfer coefficient of the composite plate under the temperature difference between day and night was analyzed.Moreover the measured heat transfer coefficient is in good agreement with the theoretical calculation,and it has important reference value for engineering application.At last,the reverberation chamber method was used to test the acoustic insulation of CCC block wall with 200 mm thickness,and the sound insulation performance was evaluated basing on the Code for design of sound insulation of civil buildings.The results show that the weighted sound reduction index R_w of the 200 mm thick CCC block wall is 45 dB,which met the sound insulation requirements of partition wall ordained by the above sound insulation standards.At the same time as the building's internal partitions,its sound insulation performance level reached 6,with good sound insulation performance.