Experimental Study On Axial Compressive Properties Of Modified Adobe Masonry Reinforced By Mesh Composite

Raw soil is the most ideal building material to maintain the stability of the ecosystem in the project,which is in line with the current development concept of green environmental protection.Because its construction is convenient,easy to use local materials,low cost,good thermal insulation performance and other characteristics,so in China’s drought less rain and relatively backward economic areas are still widely used.Due to the inherent shortcomings of raw earth architecture,such as low strength,poor durability and other attributes limit its own development.At present,there are two ways to solve this problem,namely,the structure and the basic physical properties of raw soil.In terms of the basic physical properties of soil,many scholars have greatly improved its mechanical properties by adding modified materials,such as cement,lime and other chemical materials and natural materials such as wheat straw and coarse sand.The core of raw earth building is green and pollution-free,so it is considered that the modification of adobe with natural materials is more consistent with this concept.Based on the concept of"fiber concrete",this paper regards mud as cementing material,stones and coarse sand as coarse and fine aggregate,and adds flax to improve the mechanical properties of raw soil material with purpose.Firstly,the paper carried out modification tests on raw soil materials.Through the compressive strength tests on 150mm cubic test blocks with modified materials added,the following results were obtained:Compared with the unmodified test blocks,the skeleton function of the aggregate is helpful to improve the bearing capacity of the test blocks,and the reinforcing function of the flax is helpful to improve the strength and deformation capacity of the test blocks.The optimal mass ratio of soil and modified materials is soil:flax:coarse sand:stone=1:003:0.3:0.02.At this time,the compressive strength of the test block increases by 33.51%.After modification,the elastoplastic deformation ability of the test block is enhanced,and the ability of seismic energy dissipation is improved.By calculating the area enclosed by the curve and coordinate axis,the energy consumption is increased by 105.31%at most.The compressive strength of the adobe increased by 41.1%.Compared with the data of wheat straw,it was found that the strengthening effect of fiber was related to the porosity of the material itself.The compressive strength test of masonry shows that the two methods of modification and GFRP mesh material strengthening have great help to improve the strength and deformation capacity of masonry.Compared with the QST group,the strength and deformation capacity of the QGST group are increased by 23.01%and15.58%,and the strength and deformation capacity of the QGSTF group are increased by 100.88%and 32.78%.Combined with the test data and the results of existing papers,the formula for calculating the compressive strength of masonry in the code is revised.If f₁≤6.0MPa,k₁should be 0.5 when calculating the strength of masonry.When f₁>6.0MPa,k₁should be 0.78 as sintered common brick;When f₂is approximately f₁/3or smaller,k₁should take 0.5,leaving the definitions of the other parameters in the formula unchanged.After modification,the compactness of the adobe is increased,and the strength of the adobe is fully utilized by the enhancement.The two methods are conducive to the improvement of the elastic modulus of the masonry,and the improvement of QGSTF group is 99.9%compared with QST group.