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The effect of different parameters on the development of compressive strength of oil palm shell geopolymer concrete.

Kupaei RH, Alengaram UJ, Jumaat MZ - ScientificWorldJournal (2014)

Bottom Line: The pretreatment with alkaline solution did not have a significant positive effect on the water absorption of OPS aggregate and the compressive strength of OPSGPC.The result revealed that a maximum compressive strength of 32 MPa could be obtained at a temperature of 65°C and curing period of 4 days.This investigation also found that an A/FA ratio of 0.45 has the optimum amount of alkaline liquid and it resulted in the highest level of compressive strength.

View Article: PubMed Central - PubMed

Affiliation: Department of Civil Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.

ABSTRACT
This paper presents the experimental results of an on-going research project on geopolymer lightweight concrete using two locally available waste materials--low calcium fly ash (FA) and oil palm shell (OPS)--as the binder and lightweight coarse aggregate, respectively. OPS was pretreated with three different alkaline solutions of sodium hydroxide (NaOH), potassium hydroxide, and sodium silicate as well as polyvinyl alcohol (PVA) for 30 days; afterwards, oil palm shell geopolymer lightweight concrete (OPSGPC) was cast by using both pretreated and untreated OPSs. The effect of these solutions on the water absorption of OPS, and the development of compressive strength in different curing conditions of OPSGPC produced by pretreated OPS were investigated; subsequently the influence of NaOH concentration, alkaline solution to FA ratio (A/FA), and different curing regimes on the compressive strength and density of OPSGPC produced by untreated OPS was inspected. The 24-hour water absorption value for OPS pretreated with 20% and 50% PVA solution was about 4% compared to 23% for untreated OPS. OPSGPC produced from OPS treated with 50% PVA solution produced the highest compressive strength of about 30 MPa in ambient cured condition. The pretreatment with alkaline solution did not have a significant positive effect on the water absorption of OPS aggregate and the compressive strength of OPSGPC. The result revealed that a maximum compressive strength of 32 MPa could be obtained at a temperature of 65°C and curing period of 4 days. This investigation also found that an A/FA ratio of 0.45 has the optimum amount of alkaline liquid and it resulted in the highest level of compressive strength.

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FESEM photography of ambient-cured OPSGPC incorporating pretreated OPS with PVA.
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Related In: Results  -  Collection


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fig8: FESEM photography of ambient-cured OPSGPC incorporating pretreated OPS with PVA.

Mentions: However, the oven-cured specimens show better performance compared to ambient-cured specimens. The requisite cube compressive strength for SLWC of 20 MPa could be achieved in 3 days for the oven-cured specimens and the 28-day strength was about 32 MPa. The OPSGPC made from the OPS treated with 5% sodium silicate solution showed the lowest compressive strength in ambient-cured condition and that one which made from the OPS treated with 50% PVA solution established the highest compressive strength; however, the compressive strength of both specimens with OPS treated with 20% and 50% PVA produced very close results. The difference in the 28-day compressive strength between the OPSGPC specimens produced from the OPS treated with alkaline solutions and the control specimen (Designation E), both cured in ambient condition, was only about 2.7%; however, it was about 12% for the specimens made with OPS treated in 20% and 50% PVA solutions. This might be attributed to the reduction in the water absorption by the OPS as it was used as the aggregate in concrete. Figures 8 and 9 show the FESEM analysis image of ambient-cured OPSGPC including pretreated OPS with PVA and KOH, respectively. Figure 9 shows unreacted FA particles in geopolymer skeleton which cause a weaker geopolymer structure leading to lower compressive strength. This might be ascribed to the lack of alkaline activator solution due to absorption of OPS aggregates during the geopolymerization process.


The effect of different parameters on the development of compressive strength of oil palm shell geopolymer concrete.

Kupaei RH, Alengaram UJ, Jumaat MZ - ScientificWorldJournal (2014)

FESEM photography of ambient-cured OPSGPC incorporating pretreated OPS with PVA.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4228731&req=5

fig8: FESEM photography of ambient-cured OPSGPC incorporating pretreated OPS with PVA.
Mentions: However, the oven-cured specimens show better performance compared to ambient-cured specimens. The requisite cube compressive strength for SLWC of 20 MPa could be achieved in 3 days for the oven-cured specimens and the 28-day strength was about 32 MPa. The OPSGPC made from the OPS treated with 5% sodium silicate solution showed the lowest compressive strength in ambient-cured condition and that one which made from the OPS treated with 50% PVA solution established the highest compressive strength; however, the compressive strength of both specimens with OPS treated with 20% and 50% PVA produced very close results. The difference in the 28-day compressive strength between the OPSGPC specimens produced from the OPS treated with alkaline solutions and the control specimen (Designation E), both cured in ambient condition, was only about 2.7%; however, it was about 12% for the specimens made with OPS treated in 20% and 50% PVA solutions. This might be attributed to the reduction in the water absorption by the OPS as it was used as the aggregate in concrete. Figures 8 and 9 show the FESEM analysis image of ambient-cured OPSGPC including pretreated OPS with PVA and KOH, respectively. Figure 9 shows unreacted FA particles in geopolymer skeleton which cause a weaker geopolymer structure leading to lower compressive strength. This might be ascribed to the lack of alkaline activator solution due to absorption of OPS aggregates during the geopolymerization process.

Bottom Line: The pretreatment with alkaline solution did not have a significant positive effect on the water absorption of OPS aggregate and the compressive strength of OPSGPC.The result revealed that a maximum compressive strength of 32 MPa could be obtained at a temperature of 65°C and curing period of 4 days.This investigation also found that an A/FA ratio of 0.45 has the optimum amount of alkaline liquid and it resulted in the highest level of compressive strength.

View Article: PubMed Central - PubMed

Affiliation: Department of Civil Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.

ABSTRACT
This paper presents the experimental results of an on-going research project on geopolymer lightweight concrete using two locally available waste materials--low calcium fly ash (FA) and oil palm shell (OPS)--as the binder and lightweight coarse aggregate, respectively. OPS was pretreated with three different alkaline solutions of sodium hydroxide (NaOH), potassium hydroxide, and sodium silicate as well as polyvinyl alcohol (PVA) for 30 days; afterwards, oil palm shell geopolymer lightweight concrete (OPSGPC) was cast by using both pretreated and untreated OPSs. The effect of these solutions on the water absorption of OPS, and the development of compressive strength in different curing conditions of OPSGPC produced by pretreated OPS were investigated; subsequently the influence of NaOH concentration, alkaline solution to FA ratio (A/FA), and different curing regimes on the compressive strength and density of OPSGPC produced by untreated OPS was inspected. The 24-hour water absorption value for OPS pretreated with 20% and 50% PVA solution was about 4% compared to 23% for untreated OPS. OPSGPC produced from OPS treated with 50% PVA solution produced the highest compressive strength of about 30 MPa in ambient cured condition. The pretreatment with alkaline solution did not have a significant positive effect on the water absorption of OPS aggregate and the compressive strength of OPSGPC. The result revealed that a maximum compressive strength of 32 MPa could be obtained at a temperature of 65°C and curing period of 4 days. This investigation also found that an A/FA ratio of 0.45 has the optimum amount of alkaline liquid and it resulted in the highest level of compressive strength.

Show MeSH