Study on the factors effecting the Rheological Properties of Concrete Mixtures for Pumping Applications

¹ Department of Civil Engineering, Vardhaman College of Engineering, Telangana, India.
² Department of Civil Engineering, CVR College of Engineering, Hyderabad, Telangana, India.
³ Department of Civil Engineering, KG Reddy College of Engineering and Technology, Hyderabad, Telangana, India.
⁴ Department of Civil Engineering, Vidya Jyothi Institute of Technology, Telangana, India.

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 3 August 2026

Abstract

This study examines the factors influencing the rheological properties of concrete mixtures for pumping applications, focusing on yield stress and plastic viscosity, which are critical for pumpability. Experimental investigations were conducted on various mix designs, with water-cement ratios ranging from 0.40 to 0.55, aggregate sizes from 10 mm to 20 mm, and different types and dosages of admixtures. Results show that increasing the water-cement ratio from 0.40 to 0.50 reduces yield stress by approximately 35%, enhancing flow but potentially compromising strength. Incorporating superplasticizers at 1% by weight of cement decreased plastic viscosity by up to 30%, facilitating smoother pumping without adding water. Fine aggregates (passing 600 µm sieve) improved cohesion, while increasing coarse aggregate content raised yield stress by 20-25%, making pumping more challenging. Adding fly ash (15% replacement) lowered yield stress by 18%, improving workability, whereas silica fume (10% replacement) increased plastic viscosity by 15%, contributing to mix stability. Temperature increases from 20°C to 35°C during pumping led to a 12% rise in viscosity, impacting flow. This study identifies an optimal balance of mix composition to achieve desired rheological properties, offering practical insights for designing concrete mixtures with improved pumpability for efficient construction processes.