Study on Permeability Coefficient and Volumetric Deformation Modulus of Fresh Concrete for Different Mix Designs

Surface compactness poured with controlled permeability formwork liner (CPFL) depends on deformability and permeability of fresh concrete consequentially and subject to variation of wrapped formwork, self-weight stress of concrete and vibratory stress. In this paper, bulk modulus and vertical permeability coefficients are acquired from triaxial test and variable head permeability test for the first time with different mixing designs of fresh concrete. The impact factors changed, i.e. water blinder ratio from 0.4 to 0.5, mixed duration from 1 hour to 2.5 hours, coarse aggregate type with gravel and pebble, mixed volume of pulverized fuel ash from 10 to 30 percent and ambient temperature from 15°C to 30°C, were studied by orthogonal experimental design. Triaxial test results indicated that secant modulus is more suitable than tangent modulus of bulk deformation, elastic deformation and Poisson's ratio of freshly mixed concrete. Besides, permeability coefficient of mixed concrete freshly is the most influenced by water blinder ratio. It is crucial and helpful to study rheology of fresh concrete cast with CPFL in depth.