Abstract: In this study, the Compressive strength of concretes
made with Ground Granulated Blast furnace Slag (GGBS),
Pulverised Fuel Ash (PFA), Rice Husk Ash (RHA) and Waste Glass
Powder (WGP) after they were exposed 7800C (exposure duration of
around 60 minutes) and then allowed to cool down gradually in the
furnace for about 280 minutes at water binder ratio of 0.50 was
investigated. GGBS, PFA, RHA and WGP were used to replace up to
20% Portland cement in the control concrete. Test for the
determination of workability, compressive strength and tensile
splitting strength of the concretes were carried out and the results
were compared with control concrete. The test results showed that the
compressive strength decreased by an average of around 30% after
the concretes were exposed to the heating and cooling scenario.
Abstract: This work reports the potential of using Palm Kernel
(PK) ash and shell as a partial substitute for Portland Cement (PC)
and coarse aggregate in the development of mortar and concrete. PK
ash and shell are agro-waste materials from palm oil mills, the
disposal of PK ash and shell is an environmental problem of concern.
The PK ash has pozzolanic properties that enables it as a partial
replacement for cement and also plays an important role in the
strength and durability of concrete, its use in concrete will alleviate
the increasing challenges of scarcity and high cost of cement. In order
to investigate the PC replacement potential of PK ash, three types of
PK ash were produced at varying temperature (350-750C) and they
were used to replace up to 50% PC. The PK shell was used to replace
up to 100% coarse aggregate in order to study its aggregate
replacement potential. The testing programme included material
characterisation, the determination of compressive strength, tensile
splitting strength and chemical durability in aggressive sulfatebearing
exposure conditions. The 90 day compressive results showed
a significant strength gain (up to 26.2 N/mm2). The Portland cement
and conventional coarse aggregate has significantly higher influence
in the strength gain compared to the equivalent PK ash and PK shell.
The chemical durability results demonstrated that after a prolonged
period of exposure, significant strength losses in all the concretes
were observed. This phenomenon is explained, due to lower change
in concrete morphology and inhibition of reaction species and the
final disruption of the aggregate cement paste matrix.