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sur le développement des zones arides et semi-arides

Titre : Study on Physical and Mechanical Properties of Sprayed Desert Sand Concrete ——Taking the Twelve Regiments of Desert Sand in Aral as An Example

Auteur : 管裕

Grade : Master 2022

Université : Tarim University

Résumé partiel
With the implementation of policies such as the Great Western Development and the Southward Development of the Corps,the construction industry in southern Xinjiang has developed rapidly,but the shortage of construction sand resources has become increasingly prominent.Southern Xinjiang is rich in desert sand resources,and replacing ordinary sand with desert sand can alleviate the shortage of construction sand.After consulting the literature,it is found that the physical and chemical properties of desert sand cannot be directly applied to concrete.In this study,the laboratory test method was used to prepare desert sand shotcrete material by replacing ordinary sand in shotcrete in a certain proportion.The influence of desert sand replacement rate on the physical and mechanical properties of concrete and the bonding performance with the base layer and steel reinforcement,the BP model of the mechanical strength of desert sand shotcrete is established to predict the influence of desert sand replacement rate on the physical and mechanical properties of concrete,and the appropriate desert sand replacement is selected.In order to further improve the utilization rate of desert sand in shotcrete,basalt fiber was added when the desert sand replacement rate was 50%.Appropriate basalt fiber content.The research results provide a certain theoretical basis for the application of desert sand shotcrete in engineering.The main results of this research are as follows :（1）By replacing natural sand with desert sand of 0（control group）,10%,20%,30%,40%,and 50%,the effect of desert sand replacement rate on the slump and mechanical properties of shotcrete was studied.The results show that : with the increase of desert sand replacement rate,the slump of desert sand shotcrete mixture shows a trend of first increase and then decrease,the highest when the replacement rate is 10%,reaching 113 mm,and when the replacement rate exceeds 30%,the slump of the mixture has not met the specification requirements of 80～120 mm.When the replacement rate was 50%,the slump was the lowest,only 12 mm ;the overall compressive strength showed a trend of first increasing and then decreasing.When the replacement rate was 50%,the 28-day compressive strength was 38.22 MPa compared with the control group,After the replacement rate exceeds 50%,it begins to drop significantly,and when the replacement rate of desert sand is 70%,it is only 27.85 MPa,which does not meet the C30 strength design requirements ;the splitting tensile strength and flexural strength show a downward trend,and the replacement rate is At50%,compared with the control group,the 28-day splitting tensile strength and flexural strength decreased by 50.68% and 15.97%,respectively

Mots clés : desert sand ;replacement rate ;mechanical properties ;bond strength ;

Présentation (CNKI)