A Study on Temperature Stress Control Measures of MgO Concrete Dam

In recent years, the method of preventing cracks in dam body by adding Magnesium Oxide (MgO) to concrete has attracted more and more attention. This method makes full use of the delayed micro expansion characteristics of MgO to reduce or compensate the shrinkage deformation of concrete, reduce the tensile stress of concrete dam, and then effectively reduce the possibility of dam cracking. This paper studied the theoretical basis of using MgO to compensate for heat shrinkage, control thermal stress, and limit concrete cracking. After that, an exper-imental study on the deformation characteristics of MgO con-crete was carried out, and the mathematical model of autoge-nous volume deformation of MgO concrete is introduced. Finally, with the Linxihe project as the background, a Three-dimensional Finite element method (FEM) numerical simulation model was established to consider the thermal stress compensa-tion efficiency of MgO concrete by different content. The calcu-lation results show that using the expansibility of MgO concrete to create effective compressive stress in mass concrete can con-trol thermal stress and improve the crack resistance. The re-search results have promoted the search for solutions to control temperature and prevent cracking of concrete dams, provided support for more accurate effective concrete dam construction measures.

I. INTRODUCTION

II. CONCRETE THERMAL CRACKING AND PREVENTION

A. Cracking phenomenon of concrete

B. Measures of cracking prevention

C. Application of MgO concrete in arch dams

III. EXPERIMENTAL STUDY ON THE AUTOGENOUS VOLUME DEFORMATION OF MGO CONCRETE

A. Expansion mechanism and characteristics of MgO concrete

B. Experimental results of the AVD process of MgO con-crete

C. The mathematical model to simulate the AVD process

IV. EVALUATE THE THERMAL STRESS CONTROL EFFICIENCY OF MGO CONCRETE DAM

A. Finite element mesh

B. Analysis of the effect of MgO content on thermal stress field

V. CONCLUSION

ACKNOWLEDGMENTS

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Detail:  A Study on Temperature Stress Control Measures of MgO Concrete Dam

International Journal of Engineering Research & Technology (IJERT)
ISSN: 2278-0181
Vol. 9 Issue 06, June-2020