Experimental Study On Non-load-bearing Wall Materials Formed By 3D Printing

3D printing,also known as rapid prototyping,is a technology that can add materials layer by layer and is known as the core of the third industrial revolution.It is widely used because of its fast constructing speed,low cost and it is environmental-friendly.In addition,3D printing technology is of great significance to the construction of rural residence,villas,affordable housing and low-rent housing,high-rise housing,emergency housing,wind and sand fixation,and space bases.3D printing technology has extremely high requirements for materials,and materials are the key to the development of 3D printing technology.In this thesis,through a series of experiments,the key technical performance of 3D printing wall materials is studied,and a mix ratio suitable for 3D printing non-load-bearing wall materials is determined.The main research contents of the thesis are as follows:(1)For new materials such as sulphoaluminate cement,tailings sand,desulfurized gypsum,and powdered polycarboxylic acid-based water-reducing agent,orthogonal test methods are used to measure the cubic compressive strength and compression ratio of 3D printed non-load-bearing wall materials.Also,experiments are conducted to test the tensible bond strength of the material range and variance analysis of 3D printing wall materials 3d,7d,28 d compressive strength,fold-compression ratio,and tensile bonding strength of the optimal content of the key components of the material is obtained.(2)Through orthogonal experiment and correlation analysis of material bond strength,the author measured the mortar setting time for six groups of mix ratios.After taking into consideration of the features of 3D printing,the author has worked out the best mix ratio of the materials.(3)The original ratio and the new ratio were used to print non-load-bearing walls using the 3D wall printer developed by the cooperative unit.The printed walls were tested for their compressive strength after standard curing for 28 days,and they all met the requirements for the bearing capacity of ordinary block masonry walls in the “Code for Design of Masonry structures”.(4)The direct stretching method was used to measure the interlayer bonding strength of the two walls with the standard curing for 28 days.The results all met the requirements of the current mortar technical regulations for the bonding strength.The new method can shed some lights to the future intensity test for the interlayer bonding of 3D printed walls.