SCGC Concrete (Self Compacting Geopolymer Concrete) has the advantage of being easier and more effective in casting, so it can be applied to strengthening building structures, including the Concrete Jacketing method and voute / haunch beam. This reinforcement method is a form of composite concrete application with different concrete ages, which consists of existing structures with conventional concrete material and jacket or haunch section with SCGC concrete material. This study aims to determine the characteristics in the form of direct tensile strength, flexural tensile strength, and pull off tests (bond test) to test the strength of adhesion between concrete joints. Making specimens consists of 4 x 4 x 16 (cm) flexural tensile test beams, and 15 x 15 x 60 (cm) pull off specimens, and direct tensile specimens in the form of numbers 8. The principle of making test specimens is done by casting twice The first casting is done on the first half of the mold, then wait until the concrete age is 28 days. Then a second casting is carried out in the next half, until the concrete age is 28 days. So that the total age of concrete in making connection test specimens is 56 days. From the results of this study it was found SCGC concrete has a higher adhesion than conventional concrete so that SCGC concrete can be applied for structural reinforcement.

This study analyzes the effect of white soil as a substitution of fly ash on geopolymer binders. Fly ash from Tanjung Jati Jepara, white soil from Kupang, water and NaOH as alkaline activators are mixed into binders and tested for setting time with a Vicat tool. The water factor of the binder was used 0.5. The white soil substitution in fly ash using a percentage of 0 to 30 of the weight of fly ash. Fly ash and white soil used had the particle size smaller than 0.074 mm or passed the number 200 sieve and had a moisture content of 0%. The results show that the setting time of geopolymer binder with substitution white soil in the range of 52.5 to 105 minutes for the initial setting time and is between 180 to 225 minutes for the final setting time. This value approaches the same as the setting time of Portland cement in SNI 15-2049-2004. From the 7 variations tested, the binder with 15% of white soil has a faster setting time compared to other variations, i.e 52.5 minutes for initial and 180 minutes for final setting time. The temperature when testing affects the setting time of the geopolymer binder

This study analysed the effect of white soil as a filler on geopolymer mortar. The materials used were fly ash, white soil from Kupang as fillers, sand, water, and NaOH as alkaline activator. The comparison of geopolymer mortar mixture was 1 Pca: 3 Sand with water factor 0.5. The Pca was composed by white soil and fly ash with alkaline activator and water. The percentage of white soil used were 5, 10, 15, 20, 25 and 30%. The white soil chosen passed the number 200 sieve. Moreover, the dimension of mortar used was 5 x 5 x 5 cm. To remove the water content from the mortar, the oven was set at 60 °C for 24 hours until the mortar weight did not change. The result shows that porosity decreases with the increase of white soil percentage. Increase in the white soil percentage by 5, 10, 15 and 20% can reduce porosity by 0.9, 2.7, 2.5 and 2.9%. Nevertheless, the white soil, with a percentage of 25 and 30, increased porosity by 3.7 and 3.8%, respectively. This happened because in these percentages, the white soil hardens faster than the other percentages, impacting the compaction process on the mould.

The use of industrial waste as a component of nowadays building material has become of major importance due to the underlining of environmental and sustainability issues. Among these materials is Ground Granulated Blast Furnace Slag (GGBFS), often referred to as slag-cement. The material is a residue produced during the steel refining process. The cementitious nature of the product makes it most suitable for ordinary Portland cement (PC) substitution. However, the behavior of this slag-cement in terms of development time and strength has not been defined in great details. In the construction industry, time is of major importance, a prolonged hydration process could delay the overall process. This research work focused on the setting time and strength response of slag-cement in mortar. The ratio of mortar constituent of cement-to-sand was 1 : 3. The percentage of slag-cement substitute to PC was 0%, 25%, 50% and 75% to the cement weight. The compressive strength was tested at the age of 14 days and 28 days. The results of the analysis showed that at a 25% slag-cement substitution a very significant increase in strength was shown. The increase was more pronounced at the age of 28 days when compared to 14 days and recorded to be 31.90%. As for the 50% and 75% slag-cement substitution, no significant increase in strength improvement was noticed. The test results showed a 2.66% enhancement for the 50% slag- cement substitution and a 2.45% increase for a 75% slag-cement replacement. The study also showed that slag-cement required a higher water-cement factor for the normal consistency