A case study on examining the fresh-state behavior of self-compacting mortar containing waste powders from various sources

Abstract

In recent years, sustainable construction materials have gained significant attention, with Self-Compacting Cementitious Mixes (SCCM) emerging as a promising alternative due to its ability to self-settlement. For eco-friendly practices, blending SCCM with waste powders (WPs) not only promotes recycling but can improve efficacy of the mix. Though, the fresh-state behavior of such blends remains insufficiently explored. Therefore, in this study, the fresh-state behavior of self-compacting mortar (SCM) investigated when blended with various WPs, i.e., brick, concrete, flyash, and marble powders distinctly, replacing cement up to 30%. Additionally, waste tire rubber (WTR) fiber is introduced, replacing 10% of the fine aggregate. The rheological characteristics of waste incorporated SCM is investigated through two distinct mix series. In Series I, various WPs substitute a portion of the cement. In Series II, WTR fiber replaces 10% of the fine aggregate, while also partially substituting the cement. The integration of WP and WTR fiber modulate the rheological parameters, notably impacting the static yield stress, dynamic yield stress, and plastic viscosity. Within Series-I, the amalgamation of waste brick and marble powders yielded the peak escalation in both static and dynamic yield stresses, registering increments of 424.02% and 210.24%, respectively, relative to plain SCM. Conversely, in Series-II, solely the waste brick powder marked the zenith in these stresses, recording surges of 351.29% and 119.64% respectively, in relation to the plain SCM. Mix FA30R possesses the lowest rheological parameters making it the best SCM mix. Notwithstanding the augmented exertion necessitated by the WP-augmented mixes to achieve optimal flow, every mix manifested pseudoplastic and thixotropic tendencies. Therefore, these findings underscore the feasibility of waste repurposing in construction endeavors, ensuring field flow prerequisites are met.