Rheological and Mechanical Properties of Self-Compacting Concrete with Partial Replacement of Marble Slurry and Fly Ash

Continuous increase in the marble waste production and high carbon emission of the cement affects the environment. The use of marble waste in concrete as replacement of fine aggregate and the substitution of cement with supplementary cementitious material (i.e., fly ash) reduces the carbon emission and cost of concrete and promotes sustainable growth. The paper investigates the effect of partial replacement of marble slurry with natural fine aggregates and fly ash as supplementary cementitious material (SCM) on the rheological and mechanical properties of self-compacting concrete. The workability of self-compacting concrete was measured through slump flow, V-funnel, and L-box. The hardened property includes compressive strength under the curing of 7 and 28 days with a target strength of 25 MPa. A set of concrete mixes was considered for finding the optimum mixes through the basic fresh properties. Rheological parameters like yield stress and plastic viscosity were evaluated for the critical mixes. The mixes that validate the linear and nonlinear relations of flow were evaluated by studying the Bingham and modified Bingham model. Polycarboxylate Ether (PCE)-based superplasticizer (SP) was added to disperse the agglomerated cement and marble slurry (MS) particles to reduce the higher demand of water to binder (w/b) ratio. The PCE based SP contains inbuilt viscosity modifying agent (VMA) to control the static segregation of mixes. The influence of thixotropy under static and dynamic conditions describes the nature of interparticle bonding. The paper validates the critical flow path that a concrete mix follows through parametric evaluation at an optimum w/b ratio so that the mixes behave like pumpable concrete, along with reduced formwork pressure at the site.