Skripsi
CHARACTERISTICS OF GEOPOLYMER ARTIFICIAL AGGREGATE USE IN NORMAL CONCRETE
Concrete is a very important element and is widely used in various construction work industries, but concrete has a weakness: its specific gravity is quite large (2200 – 2500 kg/m3). In concrete, aggregate occupies 60% -80% of the concrete volume, affecting the specific gravity of the concrete. Using lightweight aggregate is one way to reduce weight and increase the strength and durability of concrete. In Indonesia, coal fly-ash (CFA) availability is relatively abundant, but the utilization level is still low, causing environmental problems. To overcome this, CFA can be used as a raw material for making polymer artificial ligtweigth aggregates (PLA). In this research, PLA was made by mixing CFA taken from PT. Pupuk Sriwijaya with epoxy resin hardener (ERh) which has low viscosity and meets ASTM standards with a ratio of 2:1. In this research, PLA was made by mixing CFA taken from PT. Pupuk Sriwijaya with Epoxy Resin + Hardener (ERh) which has low viscosity and meets ASTM standards with a ratio of 2:1. The resulting PLA will have characteristics like natural coarse aggregate (split), both in terms of specific gravity and compressive strength. The PLA manufacturing process is carried out using a simple mixing method using 15 different compositions. The ratio between CFA: ERh is 50:50; 55:45 ; 60:40, 65:35 ; 70:30 ; 72:28 ; 74;26 ; 76:24 ; 78:22 ; 80:20 ; 82:18 ; 84:16 ; 86:14 ; 88:12 ; 90:10. Hardening time (PLA) was taken for 6 hours, 12 hours, 24 hours, 3 days, 7 days, 14 days, 21 days, and 28 days, each with a total of 1200 test objects. Based on the 15 PLA compositions made, 3 PLA compositions were selected which had a hardening time of 6 hours, specific gravity of 1400-1800 kg/m3, and met the standards for compressive strength of structural concrete (>17 MPa). PLA_70:30 is used as a substitute for coarse aggregate for lightweight concrete with a quality of 30 MPa, PLA_76:24 with a concrete quality of 20 MPa, and PLA_80:20 with a quality of 17.5 MPa. The use of PLA in lightweight concrete mixtures can reduce the bulk weight of concrete by 12.72%. The compressive strength produced by concrete using PLA_76:24 and PLA_80:20 can meet the planned compressive strength quality, but PLA_70:30 does not meet the planned quality compressive strength. From the results of SEM tests carried out on lightweight concrete samples, the bond between PLA_70:30 and the mortar in lightweight concrete looks weak; this is due to the smooth texture of PLA_70:30 with tiny pores causing the adhesive strength of the mortar. PLA_70:30 is weak and affects the compressive strength value of the resulting concrete. The results of durability testing using sulfuric acid and brackish water immersion showed that lightweight concrete had higher resistance than normal concrete; however, the resistance of lightweight concrete to high temperatures with combustion for 3 hours was lower than that of normal concrete. This decrease was caused by the PLA used in lightweight concrete mixtures containing epoxy resin susceptible to high temperatures (fire). Apart from that, the age of PLA when used in lightweight concrete mixtures does not significantly influence the strength of the concrete.
| Inventory Code | Barcode | Call Number | Location | Status |
|---|---|---|---|---|
| 2407003700 | T146261 | T1462612024 | Central Library (Reference) | Available but not for loan - Not for Loan |