Mukaila Yinka Sanni, Ocholi Amana and Pinder Ejeh Stephen

Mukaila Yinka Sanni, PhD scholar, Civil, Department of Civil Engineering, Ahmadu Bello University Zaria, 810001, Kaduna State, Nigeria, sannimukaila@yahoo.com
Ocholi Amana, Associate Professor, Department of Civil Engineering, Ahmadu Bello University Zaria, 810001, Kaduna State, Nigeria, amanaocholi@gmail.com
Pinder Ejeh Stephen, Professor, Department of Civil Engineering, Ahmadu Bello University Zaria, 810001, Kaduna State, Nigeria, engrdrejeh@yahoo.com

ABSTRACT
In this study, the thermal and dynamic thermal performance of crumb-rubber modified masonry hollow concrete blocks and wallette’s with mortar plaster on both sides as surface finishing was
investigated. An investigation was carried out on the plain reference and modified samples with varying content of non-biodegradable waste tyre (crumb-rubber) partially substituted for coarse aggregate (granite) by volume at 0%, 5%, 10%, 15%, 20%, and 25%. Thermal properties were measured based on the Non-steady state using a KD 2 Pro thermal analyzer while the dynamic thermal properties were evaluated using the ‘dynamic thermal properties calculator’ software tool. Result reveals that the thermal conductivity of reference masonry hollow concrete block units (1.380W/mk) has been greatly reduced to 0.610W/mk indicating 55.8% reduction while heat capacity, diffusivity, and effusivity decreased by 43.3%, 53.8%, and 55% respectively. Furthermore, the combined thermal admittance (Y-value) of the modified blocks and mortar in form of wallette’s increased slightly with 5% replacement of crumb-rubber but decreased by 20.1% with further increase in crumb-rubber content up to 25% also the result reveals that the thermal transmittance (U-value) decreased continuously by 13.8% while the thermal decrement was not significantly affected but the associated time lag increased considerably which could offer a significant reduction in temperature fluctuation which is very important in terms of building thermal efficiency and comfort.

KEYWORDS: rubberized concrete blocks, wallette’s, mortar, thermal, dynamic thermal,