Study On Mechanical Properties Of Grouting Anchor Rod Of Dry Charcoal Sand Of Carboniferous Group

With the progress of China’s economic and social construction,the construction industry has entered a period of rapid development.As a common building material,mortar consumes a lot of natural sand and wastes in production,resulting in resource shortage and environmental pollution.Traditional mortar has many drawbacks.Developing and developing high quality dry mortar can help improve the quality of mortar.And performance,can alleviate environmental pollution,improve the status quo of resource consumption,and have social and economic significance.In this paper,the experimental study has determined the optimal gradation of the mechanism sand.Under this grading,dry mortar with different lime sand ratio and mechanism sand instead of natural river sand substitution rate is prepared,and its working performance,mechanical properties and mortar anchor The mechanical properties of the anchor were studied and the relevant conclusions were as follows:1.The effects of different particle size fractions on the physical and mechanical properties of dry mortar were studied experimentally.The particle size of the sieved sand was divided into eight groups,and the physical and mechanical properties of different dry mortars were tested.test.According to the test results,it is concluded that the dry mortar has the best comprehensive performance when the sand content of the four particle size mechanisms is 30%,40%,10% and 10%.2.Experimental study on the effect of the ratio of lime sand ratio and mechanical sand replacing natural sand on the physical properties and mechanical properties of the mechanical sand dry mortar.The results show that:①Under each mechanism sand substitution rate,the lime sand ratio reduces the apparent density,consistency and fluidity of the dry mortar.When the ratio of lime to sand is 1:4,the mortar is hard to form and is prone to fracture.Dissolution;the replacement rate of the mechanism sand increases under different lime sand ratio,the apparent density of the mortar increases,and the consistency and fluidity of the mortar decrease.The mortar mixed with natural sand has less water consumption,the surface is moist and the fluidity is better,and the mechanical mortar is thicker and thicker.②Under different sand substitution rates,the smaller the sand-cement ratio,the smaller the mortar strength.Under different lime-soil ratios,the compressive and flexural strength of the mortar under the small mechanism sand substitution rate does not change significantly,showing a small Fluctuating,and the mortar strength decreases sharply when the replacement rate of the mechanical sand exceeds 60% to 70%.In order to ensure the strength of the mortar in the actual project,the content of the mechanism sand in the fine aggregate should not exceed 70%.3.Experimental study on the bonding parameters of different diameter steel bars and proportioned mortar grouting anchors,the results show that:①When the anchor mortar is the same,the larger the steel bar diameter is,the larger the bonding parameter of the anchoring system is.The bond strength and residual friction stress of 10 mm steel bar are 76% and 89.5% of the 25 mm steel bar respectively;the steel bar type has the most significant effect on the anchoring effect.The ribs are made of light round bars,and the values of the bonding parameters are greatly reduced.②When the diameter of the steel bar is the same,the anchoring parameters of the mortar are increased first and then decreased.The anchoring parameters are the largest when the ratio of lime to sand is 1:3.The higher the replacement rate of the mechanism sand is,the higher the mechanical ratio of the mechanical sanding.The more significant,the maximum value of each bonding parameter is when the replacement rate is 100%.