INFLUENCE OF METAKAOLIN ON THE RESISTANCE OF CEMENT MORTAR TO ELEVATED TEMPERATURES
INFLUENCE OF METAKAOLIN ON THE RESISTANCE OF CEMENT MORTAR TO ELEVATED TEMPERATURES
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Date
2017
Authors
USMAN, J. IBRAHIM, M.M. IBRAHIM, A.G. MUAZU, U.
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Abstract
Ordinary Portland cement mortar exposed to elevated temperature experiences physico-chemical changes that can
lead to the deterioration of its strength and durability performance. However, the inclusion ofpovgplanic material
in cement mortar modifies the response of mortar to elevated temperatures. This paper examined the effect of
metakaolin (MK) on the resistance of cement mortar to elevated temperatures. Two sets of cement mortar
specimens, one with 20% MK replacing cement (MK-specimen) and the other without MK (control) were
produced. Constant aggregate to cement ratio of 2.75 and water to binder ratio of 0.35 were used to produce the
mortar specimens. After 28 days of curing in water and pre-heating at 105°C for 24 hours, the two sets of
specimens were heated to different temperatures of 200, 400, 600 and 800°C at a constant heating rate of
2.5"C/min. After achieving the targeted temperatures, the specimens were maintained for 2 hours before cooling to
ambient temperature in the furnace. The compressive strengths and ultrasonic pulse velocities of the heated
specimens were tested The results showed that the retained compressive strengths of the MK-specimens at 200,
400, 600 and 800"C were 104%, 74%, 68% and 42%, respectively while, the corresponding values for the
control specimens were 101%, 67%, 55% and 45%. Moreover, the retained pulse velocities values for the MKspecimens
were 95%, 74%, 44% and 36%, while those for the control specimens were 91%, 70%, 41% and
33% at the same temperatures. Impliedly, MK improved the retained compressive strength and pulse velocity of
cement mortar at elevated temperatures. Therefore, cement mortar blended with MK may be used as afire resisting
construction material.
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Department of Building, Ahmadu Bello University, Zaria 4Department of Building Technology, Federal Polytechnic, Kaura Namoda, Zamfara Corresponding author; jamilonline05@gmail.com Tel: +2347035740454