Influence of the Recycled Concrete Aggregate Features on the Behavior of Eco-Efficient Mixtures

Influence of the Mix Proportion and Aggregate Features on the Performance of Eco-Efficient Fine Recycled Concrete Aggregate Mixtures

“…Recently, a new mix design procedure, the so-called equivalent volume (EV) method, was developed by Ahimoghadam et al 2020 based on the main concepts of the previous EMV and EMV-mod methods. The EV was established to solve the issues faced by EMV and EMV-mod mix-proportioned mixtures in the fresh state, along with providing recycled mixtures with an eco-friendly character and suitable performance in the hardened state [31]. The novelty of this method is that the RCA-proportioned mix is based on a companion conventional concrete displaying the same volumetric amount of cement paste and aggregates (fine and coarse), while in the EMV (and EMV-mod), the same amount of coarse aggregates and mortar was considered for calculations.…”

“…Hence, the total volumetric cement paste content in an EV-proportioned mixture is defined as the summation of residual and fresh-paste volumes. As opposed to EMV and EMV-mod methods, EV-proportioned mixes often yielded suitable fresh-state behaviour and cement efficiency (PC contents of about 300 kg/m 3 ) due to the significant increase in fine aggregates and decrease in coarse particles in the system [31,41].…”

“…The EV method [31] was adapted to design recycled mixture and accounting for the RCP content attached to the fine aggregate main concept of the EV technique was kept the same as follows: t mixture is based on a conventional mixture, having the same am ment paste and aggregates. In other words, the total amount of mix is considered as the summation of the RCP plus the fresh pas contrast, the total volume of aggregates is the volume of original v A total of three distinct concrete mixtures (i.e., DRM, EV and PPM) with 100% replacement of fine NA by FRCA were designed.…”

“…In this context, advanced mix design techniques have been developed to optimize recycled concrete mixtures, allowing more efficient re-use of RCA in concrete and enabling better performances in the fresh and hardened states. The literature suggests that the key factor for an efficient proportioning of recycled concrete mixtures bearing CRCA is to account for their unique microstructure (i.e., original virgin aggregate-OVA and residual mortar-RM), while the mix design and proportioning techniques such as the equivalent mortar volume (EMV) [30] and equivalent volume (EV) [31] methods were established with this concept and showed promising results. Likewise, particle packing models (PPMs) have demonstrated to successfully proportion recycled mixtures bearing CRCA with suitable fresh-and hardened-state properties [32].…”

A Review of Current Design and Construction Practice for Road Kerbs and a Sustainability Analysis

“…Along with the suitability of different kerb materials from a mechanical behaviour point of view, it is also important to assess the sustainability of using those materials. Over the past few decades, there have been significant research efforts on recycling waste products in construction [138]. Construction and demolition wastes and TDA have been shown to have promising potential.…”