Performance Evaluation of Wet Paving Concrete Incorporating Ternary Blends of Alluvial Tuff and Limestone Aggregates Using Simplex Centroid Mixture Method

Abstract

Incorporating the blends of aggregates from local quarries is inevitable for sustainable construction of concrete structures. In the present study, the performance of wet paving concrete (WPC) made with ternary blends of alluvial tuff (AF.Agg) and crushed limestone aggregates (LSLQ and LSHQ) were investigated using the simplex centroid mixture method (SCMM). The performance of WPC including the compressive strength (f_c), fracture energy (G_C) in compression, durability factor (D_f) after 300 freeze-thaw (FT) cycles in water, and the coefficient of thermal expansion (CTE) were measured according to the standard test procedures. A novel procedure was developed to measure the weight loss (W_L) and water absorption (W_A) of sawn cut prisms (SCPs) under the harsh exposure condition including 50 continuous salt-FT cycles with the high temperature gradient (−24 to +24 °C). The procedure was more destructive after a shorter exposure time. Non-linear correlations established between G_C & W_A with W_L indicating the pivotal role of interfacial bond in the long-term durability of WPC. The direct relation between W_L and W_A confirmed the porosity evolution of concrete matrix under the harsh exposure. The meaningful correlations were found between CTE and the other responses implying that an increase in CTE due to the presence of altered siliceous-based minerals within the aggregates have led to the weak interfacial bond of aggregate-paste under mechanical loads and eventually the earlier pop-out of particles under the harsh exposure. The empirical models were developed with the significant predictability to estimate the optimal blending ratio without compromising the concrete performance.