Effect of seasonal weather on the properties of geopolymer mortar

![CDATA[Despite proven to exhibit excellent mechanical properties, fresh geopolymer paste is highly viscous and displays low workability, which has become a major obstacle for it to be widely accepted for larger structural application. For cast-in-place applications, geopolymer concrete requires to be cured at ambient temperatures. Temperature and humidity varies in different seasons. The humidity variation has been found to have influence on the occurrence of white efflorescence on geopolymer samples. However, effects of temperature on efflorescence have received little attention, although temperature effects on strength are well-known. This paper will investigate the effect of a change in seasonal temperature on the properties of geopolymer mortars. The investigated properties include workability, compressive strength and efflorescence. Mini slump tests method will be carried out to determine the effect of adding extra water and commercially available superplasticisers (SP) on the flowability of geopolymer mortar. From the obtained test results, it was found that SIKA Visco Crete PC HRF – 2 has achieved the highest relative slump as compared to the reference mix RM8. Regarding strength development, it was observed those samples cured in hot (summer) conditions are more desirable to cure geopolymer mortar. Also, specimens cured under lower temperature curing conditions and low in humidity had formed white efflorescence after 7 days curing period, and rapid growth was observed over the period of 28 days curing cycle.]]