Two-Year Non-Destructive Evaluation of Eco-Efficient Concrete at Ambient Temperature and after Freeze-Thaw Cycles

Mohammed A Abed,B H Abu Bakar,Rita Nemes,Bassam A Tayeh

doi:10.3390/su131910605

Abstract

The increasing demand for eco-efficient concrete puts pressure on the industry to innovate new alternatives for its constituent materials. Coarse recycled concrete aggregates (RA) and supplementary cementitious materials (SCMs) are considered promising substitutes for coarse natural aggregates (NA) and cement, respectively. Using destructive and non-destructive testing methods, the present work aims to evaluate the effect of RA and different types of waste SCMs on the long-term performance of self-compacting high-performance concrete (SCHPC). Twenty-one mixes that were prepared with a 0.35 water-to-binder ratio were tested for their compressive strength, surface hardness, and ultrasonic pulse velocity. These tests were conducted over a two-year period at ambient temperature and again after exposure to up to 150 freeze–thaw cycles. Study findings demonstrated the possibility of developing eco-efficient SCHPC mixes using RA and waste SCMs. In addition, correlations have been introduced for predicting the compressive strength of SCHPC.

Highlights

Concrete is considered one of the most used materials in construction
The pozzolanic activity is promoted once water is supplied by recycled concrete aggregates (RA), which develops the compressive strength over time; some supplementary cementitious materials (SCMs), due to their particle porosity and irregularity characteristics, create weak points in the hardened matrix due to their pore structure [30]
Results are presented in the form of relative residual properties, where they are recorded as relative residual compressive strength, relative residual Rebound Values (RVs), and relative residual Ultrasonic Pulse Velocity (UPV), respectively, i.e., relative residual

Summary

Introduction

Concrete is considered one of the most used materials in construction. This is owed to its versatility in application and properties. The endless demand for natural resources for concrete production creates concerns for the environment. The production of a significant amount of construction wastes increases the environmental burden. The use of recycled waste construction materials in concrete fabrication is considered a key solution that could lessen the burden placed on the environment and the economy [4]. Alternatives for quarried aggregates usually take the form of recycled materials (i.e., recycled concrete aggregate). These materials could alter the fresh and hardened concrete properties

Objectives

Methods

Results

Conclusion