# Effect of Cement Content on the Deformation Properties of Cemented Sand and Gravel Material
###### Abstract  
Knowing the deformation properties of cemented sand and gravel (CSG) material can help construct reasonable constitutive models for the material, which can be used to simulate the structural performance of various practical projects including CSG dams. In this study, to investigate the effect of cement content on the deformation properties of CSG material, we employ triaxial compressive tests for cement contents of 20, 40, 60, 80, and 100 kg/m\({}^{3}\) with a confining pressure range of 0.3-1.2 MPa, and theoretically analyze the results by the regression analysis prediction method. Here, we show that both cement content and confining pressure influence the deformation properties of CSG material: for an increase in cement content, the failure strain decreases and brittleness of CSG material increases; the initial modulus of the CSG material increased exponentially with increasing cement content or confining pressure; the peak volumetric strain and its corresponding axial strain increase linearly with increasing confining pressures, which decrease with increasing cement content; the initial tangent volumetric ratio can also be determined by the peak volumetric strain and its corresponding axial strain. c 2019 9 2369 2369 2019  
cement content, density, and other mix design indexes on shear strength by triaxial shear tests of CSG material [5; 6]. [PERSON] et al. analyzed the stress-strain characteristics of CSG material with different cement contents, and the following conclusions were obtained: the axial strain corresponding to the failure strength decreased with increase in cement content; when the cement content was less than 1.5%, CSG material would mainly shrink, and when the cement content was more than 1.5%, the material displayed obvious dilatancy; the specimen showed obvious strain softening; cohesive force, strength, and stiffness increased with increase in cement content [7; 8; 9]. [PERSON] et al. successively carried out triaxial shear tests for the analysis of stress-strain curve characteristics for different cement contents [10]. [PERSON] et al. studied mechanical properties, such as the failure strength and initial elastic modulus, under the influence of confining pressure [11]. [PERSON] et al. carried out a large-scale triaxial shear test on CSG material and analyzed the influence of curing age on peak strength and stress-strain curve characteristics [12]. [PERSON] et al. conducted static and dynamic triaxial tests on CSG material for different cement contents and studied the influence of cement content and confining pressure on the static and dynamic characteristics of CSG material [13]. The abovementioned studies on the mechanical properties of CSG material focused on the change trends of peak strength, stress-strain curve, and volumetric-strain-axial-strain curve under different confining pressures, curing ages, cement contents, or aggregate gradations. The cement content is thus one of the most important factors influencing CSG properties; most qualitative analyses of CSG materials are carried out with cement contents of 60 and 80 kg/m\({}^{3}\), which are commonly used in CSG dam engineering [13]. [PERSON] et al. only considered the influence of different cement contents on the strength characteristics of CSG material and the corresponding strength expression [14]. However, the expressions for the deformation characteristics of CSG material under different cement contents, which can also indicate the relationship of deformation characteristics among rockfill material, roller compacted concrete, and CSG material, were not given. In addition, for other cemented granular materials, some scholars have also studied mechanical properties [15; 16; 17; 18; 19; 20; 21; 22]: [PERSON] et al. considered the effect of cement content by conducting a triaxial test, and the results showed that the failure strength and its corresponding strain value were less than the corresponding results of the undrained tests; [PERSON] et al.