Expansive soil improver, improved expansive soil and preparation method

Abstract

The invention provides an expansive soil improver. The expansive soil improver comprises 5-15% of biochar based on the total weight of dry expansive soil to be improved by the expansive soil improver, and the biochar is any one of wood chip biochar or pig manure biochar. The invention also provides a preparation method of the expansive soil improver. The method comprises the following steps of: pyrolyzing the biochar for two hours at the temperature of 400 DEG C under an anoxic condition; hammering the pyrolyzed biochar; sieving the pyrolyzed biochar by a 2mm sieve; and placing the biochar in a drying oven at the temperature of 105 DEG C for more than 15 hours. The invention also provides improved expansive soil and a preparation method thereof. The improved expansive soil is prepared by mixing the following raw materials in parts by weight: 100 parts of dry expansive soil to be improved; 5-15 parts of expansive soil improver; and a plurality of parts of deionized water. The expansive soil improver disclosed by the invention has the advantages of easily available materials, low cost, environmental friendliness, easiness in mixing and the like; and the improved expansive soil obtained according to the expansive soil improver is good in mechanical and engineering performance, and the expansion and shrinkage rate is inhibited.

Description

technical field [0001] The invention relates to the field of civil engineering materials, in particular to an expansive soil modifier, improved expansive soil and a preparation method. Background technique [0002] Expansive soil is a special soil rich in mineral components such as kaolinite, montmorillonite and illite, which is a highly water-sensitive and porous multi-phase medium. Expansive soil has strong water sensitivity, water absorption expansion, dehydration shrinkage and repeated deformation. In engineering construction, expansive soil often causes damage to engineering buildings, which is one of the worldwide problems in the field of geotechnical engineering. It is called "Cancer in Engineering". According to relevant research, the economic loss of our country due to geological disasters of expansive soil is about 15 billion U.S. dollars every year. [0003] At present, soil replacement method, soil property improvement method, slope reinforcement method, water ...

AI Technical Summary

Problems solved by technology

However, there are still various problems such as being unfriendly to the environment or the mechanical properties of the prepared improved soil cannot meet the requirements.

The slope reinforcement method is often used in slope engineering in expansive soil areas, using inorganic materials such as lime and cement for improvement and reinforcement. However, lime and cement modified expansive soil have the disadvantages of uneven mixing and environmental damage, and will lead to greenhouse effects, Ecological crisis and other problems are becoming more and more serious

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