Study Shows Rice Husk Ash Can Partially Replace Cement For Greener Concrete

A team of researchers from ten universities, including the American University of Ras Al Khaimah (AURAK), has explored using rice husk ash (RHA) as a partial cement replacement in sustainable concrete. Their study highlights RHA's potential due to its silica-rich composition, which reacts with cement hydrates to enhance concrete strength and stability.

The production of cement, a key concrete ingredient, releases significant carbon dioxide. This study aims to mitigate these environmental impacts by finding alternatives with lower carbon footprints. Environmentalists advocate for replacing cement with more eco-friendly materials.

Machine Learning (ML) techniques were employed to develop prediction models for the compressive strength of RHA concrete. These models offer a cost-effective and time-efficient alternative to traditional methods, providing valuable insights for builders and researchers.

The second phase of the research, conducted exclusively at AURAK, examined RHA's effects as a partial cement replacement in concrete. Cement was substituted with RHA at 5%, 10%, and 15% by weight. The resulting concrete mixtures were evaluated for strength and durability in both fresh and hardened states.

Test results indicated that RHA enhances later-age compressive strength, abrasion resistance, and moisture barrier properties of concrete. Additionally, low drying shrinkage, an important durability indicator, improved significantly with RHA incorporation.

Viability of Rice Husk Ash

Prof. Roz-Ud-Din Nassar from AURAK's Department of Civil and Infrastructure Engineering stated, "As the world struggles to reduce CO2 emissions to save the planet, it is everyone’s duty to contribute to this effort. We are happy that our research makes a strong case for using RHA as a partial replacement for cement in concrete manufacturing." He emphasized that the test results support RHA's viability in producing economical, durable, and environmentally-friendly concrete mixtures.

Prof. Stephen Wilhite, Senior Vice President of Academic Affairs and Student Success and Provost at AURAK, praised the research team: "We would like to compliment the research team that contributed to this study. It is part of ongoing global attempts by different researchers to find replacements for environmentally harmful materials." He expressed confidence in continued research on RHA's use in cement replacement.

Global Collaboration

The first phase of the study involved researchers from several universities worldwide: Najran University (Saudi Arabia), University of Engineering and Technology (Pakistan), Macroview Projects (Australia), Prince Sattam Bin Abdulaziz University (Saudi Arabia), Gulf University for Science and Technology (Kuwait), Silesian University of Technology (Poland), Budapest University of Technology and Economics (Hungary), Luleå University of Technology (Sweden), and Monash University (Malaysia).

The US Geological Survey estimates that around 4 billion tonnes of cement are produced globally each year, contributing 7% to total CO2 emissions. Specifically, producing one tonne of cement generates 0.9 tonnes of CO2.

This collaborative research underscores the importance of finding sustainable alternatives in construction practices. By incorporating rice husk ash into concrete production, we can move towards more environmentally friendly building solutions while maintaining structural integrity.

With inputs from WAM