Experimental Study On Performance Of Ceramsite Foam Concrete Composite Block And Its Masonry By Grouting Method

Ceramsite foam concrete is a new type of inorganic insulation wall material with the advantages of thermal insulation,fireproof,high strength,light weight and other excellent features.It can meet modern building’s requirements of energy conservation,safety and sustainability.This paper is based on our former research,but aims to further improve the performance of ceramsite foam concrete by employing grouting technique during preparing process.This study firstly propose the preparation method of grouting foamed concrete,and then carefully select the mix ratio of binder materials and interface treatment method to prepare 300-type and 500-type ceramsite foam concrete blocks and its composite blocks.Finally,a comparative analysis is made on the properties of antifreeze and drying shrinkage of various blocks.Furthermore,the mechanical properties and thermal performance of different types of blocks are studied and compared.Main conclusions are as follows:This paper firstly analyses the effects of the water-binder ratio,fly ash content,foam content on the performance of grouting ceramsite foam concrete.The compressive strength decreases with the increase of water-binder ratio and foam content,and early strength of specimens decrease with the increasing fly ash content.Experiment results show that grouting ceramsite foam achieves the best performance when grouting paste is prepared with concrete water-binder ratio of 0.55,foam content of 50%,fly ash content of 20%.It shows that the dry density of specimens is 781kg/m3 and the compressive strength is 5.2MPa when using 500-type ceramsite as aggregate,while the dry density is 621 kg/m~3and the compressive strength is 3.9 MPa when choosing 300-type ceramsite as aggregate.The water content of the fiber cement panel and the interface treatment method has significant influence on the interfacial bond strength and compressive strength of the composite block.The results suggest that the bond strength with the core material is the highest when the water content of the fiber cement plate is 10%without the interface treatment.The drawing treatmentf the fiber cement plate can strengthen the interfacial bonding effect between core material and panel,and the interfacial bond strength increased by 20%.Moreover,the compressive strength also increased.The compressive strength of composite block is about 20%higher than that of non-composite ordinary block.The drying shrinkage level of the ceramsite foam concrete block prepared by the grouting method is only about 40%of the standard level.Under normal conditions,the ceramsite foam concrete has better frost resistance,but the higher the moisture content is,the more the relative dynamic elastic modulus decreases after the freezing and thawing cycle,so reducing the internal moisture saturation of thermal insulation wall material is an effective way to improve the frost resistance;the more moisture content the block is,greater the thermal conductivity is.The thermal conductivity of the 500-type ceramsite foam concrete is increased by about 95%when the water saturation reaches 100%from 0%.The waterproof performance of the building wall affects its thermal insulation performance significantly.Except for 300-type block masonry,the compressive strength of300-type composite block,500-type block and 500-type composite masonry are all above 5 MPa.It is conservative to use the empirical formula from"masonry structure design code"to calculate the compressive strength of masonry;the shear strength of the four types of masonry along joint is above 0.3 MPa,and the concrete block type is used.It is safe and feasible to calculate the shear strength of along joint of ceramsite foam concrete block masonry by using concrete block and autoclaved lime sand brick empirical formula.The test analysis and theoretical calculation of the thermal performance of four types of block masonry shows that the heat transfer coefficient of the composite masonry increases slightly in spite of the existence of the fiber cement plate.But the ceramsite foam concrete block prepared by the grouting method can meet the requirements of the building external wall insulation stipulated in winter cold summer hot area.The ceramsite foam concrete block can be calculated by the formula in the code for thermal design of civil buildings.