Investigating the combined effect of aggregate size and sulphate attack on producing sustainable recycled aggregate concrete

ABSTRACT

This study investigates the performance of recycled aggregate concrete incorporating different sizes and concentrations of coarse aggregate under sodium sulphate and normal water curing. Ten mixes were produced, having two control mixes of 12 to 20 mm and 5 to 12 mm coarse aggregate size. The rest of the mixes have supplementary cementitious material with 0%, 15%, 30%, and 45% substitution of respective sizes normal aggregate by recycled aggregate. The fresh recycled aggregate concrete mixes were assessed through the slump, ball penetration, and compacting factor test, which exhibited a falling trend with the percentage increase of recycled aggregate. Moreover, compressive strength and ultrasonic pulse velocity drop with the percentage of RCA increases at 7, 28, and 91-days normal curing and 5% Na₂SO₄ solution curing at 91 days. The compressive strength and ultrasonic pulse velocity of 5-12 mm coarse aggregate concrete showed improvement over 12–20 mm coarse aggregate concrete of the same replacement for both curing. However, 5% Na₂SO₄ solution curing specimens exhibit around 5–11% decrease in compressive strength and higher penetration depth than normal curing . Furthermore, the outer face of the silica fume included samples have received fewer white patches after sodium sulphate immersion.

KEYWORDS:

• Recycled aggregate concrete
• SCM
• sulphate resistance concrete
• ultrasonic pulse velocity
• sustainability
• permeability

Acknowledgments

The author would like to acknowledge the laboratory authority of Structural and Materials Engineering, which is activated by the Department of Building Engineering and Construction Management, located at Khulna University of Engineering and Technology, Bangladesh.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Md. Habibur Rahman Sobuz

Dr. Md. Habibur Rahman Sobuz is an Assistant Professor of Structural Engineering in the Department of BuildingEngineering and Construction Management (BECM) at Khulna University of Engineering and Technology(KUET), Khulna-9203, Bangladesh. He has noteworthy industrial experience in consultancy and contracting in the design and construction of multi-story reinforced concrete and composite steel structures in Bangladesh. This was followed by ten years of research experience in higher studies and then lecturing at KUET, Bangladesh. Dr. Habibur has a BSc in Civil Engineering from KUET, one of the renowned engineering universities in Bangladesh, an MSc in structural engineering from the University Malaysia Sarawak, Malaysia and he has achieved a Ph.D. in Structural Engineering from The University of Adelaide, one of the leading research group eight universities in Australia. Dr. Habibur is a leading researcher in the field of structural and material engineering. His research expertise on the flexural, strength and ductility behavior of RC Members, strengthening and retrofitting of RC members, the time-dependent performance of structures, new generation ultra-high-performance fiber-reinforced concrete (UHPFRC), concrete sustainability and durability, low-cost lightweight aggregate concrete by usingwaste materials following the material properties and structural performance of RC members.

Shuvo Dip Datta

Shuvo Dip Datta is a growing researcher in the field of structural and materials engineering as well as construction management. He graduated from the Department of Building Engineering and Construction Management (BECM), Khulna University of Engineering and Technology (KUET), Khulna-9203, Bangladesh. He has a vast research experience in the area of destructive and non-destructive tests of recycled aggregate concrete. In addition, he has already explored the area of fiber reinforced concrete, construction waste material assessment, BIM, crisis management of a project, and utilization through his international journals and conferences. Currently, he is working on material sustainability assessment, low-cost concrete production, sustainable material utilization as construction materials, robotics in construction, and artificial intelligence in construction. He was also involved in several national projects of Dhaleswari river island, Purbacal boat club, Bangladesh Naval academy extension work, etc. He was also serving as an adjunct lecturer in the department of civil engineering at North Western University, Khulna, Bangladesh.

Abu Sayed Mohammad Akid

Abu Sayed Mohammad Akid is working as an assistant professor in the Department of Building Engineering and Construction Management (BECM) at Khulna University of Engineering and Technology(KUET), Khulna-9203, Bangladesh. Currently, he is working as a graduate research assistant in the Department of civil engineering at Arkansas State University, Jonesboro, USA.