Method for preparing high-strength microbial mortar using urease-producing microorganisms

Abstract

Urease-producing microbes including Sporosarcina antarctica U R 5 3, Sporosarcina koreensis UR47, Sporosarcina sp. UR31 and Bacillus lentus UR41 were preserved in China General Microbiological Culture Collection Center on March 16, 2012, with the preservation numbers of CGMCC No.5916, CGMCC No.5915, CGMCC No.5913 and CGMCC No.5914 respectively. The method for preparing high-strength microbial mortar by using the urease-producing microbes comprises the following steps of: carrying out fermentation culture on the above four microbes and microbes including Sporosarcina pasteurii and Terrabacter tumescens in a fermentation culture medium to obtain a bacterial solution; and filling the bacterial solution, a fixative solution and a gelling solution into a sand particle system in batches to form microbial mortar of which the highest strength can reach 55MPa. The mechanical properties of the microbial mortar are superior to those of a cement base material; compared with a cement lime material with equivalent strength, the microbial mortar is higher in splitting tensile strength; the rigidity of the microbial mortar is similar to that of cement lime mixed mortar but far smaller than that of concrete; the fatigue load tolerance and cyclic loading capacity of the microbial mortar are higher than those of the cement base material; and an artificial sandstone is an inorganic material, and is not easy to age like organic materials including epoxy resin and the like.

Description

technical field [0001] The invention belongs to the field of high-strength microbial mortar preparation, and in particular relates to a method for preparing high-strength microbial mortar by utilizing urease-producing microorganisms. Background technique [0002] The grouting method is a commonly used method to strengthen masonry structures, especially the reinforcement of historical cultural relics, and lime, cement and epoxy resin are three commonly used grouting materials. Among them, the lime-based grouting material is used as the pointing material of the traditional masonry structure, which has the best compatibility with the reinforced structure. However, due to the long hardening time of the lime-based grouting material, the strength after hardening is low, so it cannot play a good role. reinforcement effect. For ordinary cement-based grouting materials, due to the need to ensure that the grouting is dense and the fluidity of the grouting material needs to be improve...

AI Technical Summary

Problems solved by technology

At the same time, after the cement-based grouting material is hardened, its stiffness and strength often do not match the reinforced structure, which is prone to secondary damage in the unreinforced area

Furthermore, the high alkalinity of cement-based grouting materials will also make the original masonry structure more prone to alkali damage.

The above deficiencies limit the use of cement-based grouting materials to strengthen masonry structures.

Organic adhesives such as epoxy resins have excellent mechanical properties and high pourability, but due to the basic material properties of organic materials such as stress, strain performance, and thermal conductivity, they are quite different from the original structure. At the same time, the reinforced material body itself Water permeability and air permeability are low, and organic materials are easy to age, just like the views stated in the Venice Treaty: modern chemical materials do not belong to precious historical buildings, and organic materials such as epoxy resin are not suitable for large-scale masonry structure reinforcement

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