Study On Physical And Mechanical Properties And Weathering Resistance Of Clay Bricks With Different Firing Temperatures

The ancient buildings in my country take wood structure and masonry structure as the main building structure.These thousands of years of masonry buildings gradually experienced severe weathering damage under the conditions of long-term freezing and thawing alternation,groundwater migration,salt corrosion,load,alternation between wet and dry.However,due to differences in construction technology,design methods,structural performance and material properties,the weathering failure rules of masonry structures are very different from those of concrete structures,and the evaluation system of masonry structure durability performance is not perfect.The lack of theoretical research results in the durability research of masonry structures has led to the lack of scientific protection and adaptive use of ancient architectural heritage in China.In this paper,the classification and grading of the weathering type of bricks through on-site investigation are tested;the mineral composition,density,porosity,porosity,pore size distribution,water absorption rate,capillary water absorption coefficient,ultrasonic speed and uniaxial resistance of the brick at different firing temperatures are tested and analyzed Basic properties such as compressive strength;simulation of freeze-thaw and salt circulation through laboratory tests.Concluded as follow:(1)The main diseases of clay bricks can be divided into seven categories: cracks and hollows,spalling,dissolution,mechanical damage,crusts,artificial pollution and discoloration,biological diseases,etc.(2)By testing the physical and mechanical parameters of clay bricks under different firing temperatures and indoor weathering simulation tests,it was found that firing temperature will affect the physical and mechanical parameters of clay bricks and the degree of destruction of freeze-thaw and salt circulation bricks.The physical and mechanical properties and the degree of freezing and thawing and salt circulation brick damage are not improved with the increase of firing temperature,but a "pit" at a firing temperature of 1000?.(3)According to the pore properties and weathering simulation tests,the bricks were evaluated for weathering resistance.It was found that the clay bricks with firing temperature of 1000? had the worst weathering resistance.The firing temperature was 700?,800? and 900?.The weathering performance is medium,and the clay brick fired at 1100°C has the best weathering resistance.