Investigation of mechanical properties of cement and mineral additives mixtures in jet grout columns

The construction industry has experienced great changes with the construction techniques that have emerged in recent years. Advances in technology are an important factor in the diversification of building materials used in the construction market. More durable structures have been started to be built against earthquake, liquefaction and different settlements, where soil improvement has been made. The decrease in natural resources, air and environmental pollution has led to the use of industrial wastes. Silica Fume (SF), Fly Ash (FA) and Blast Furnace Slag (BFS) are major effective waste materials used in cement or concrete due to their pozzolanic properties. Their usage is very common in our age of improving the soil with additives. In this study, additive-free Portland Cement (CEM-I 42,5R) and 0%, 10% and 20% of cement weight SF, 0%, 10% and 20% F type FA, 0%, 20% and 40%BFS and 0%, 1% and 2% Hyper plasticizer (HP) binder material with sand were used and 81 different mortar samples with a water / binder ratio of 0.8 were prepared from their mixtures. After the preparation of samples which were kept for 28 and 56 days without changing the humidity, unconfined compressive and splitting tensile (Brazilian) strength tests were carried out on them. In addition, 16 designs that can be mixed in optimum values and Jet Grout have been determined and Jet Grout column has been created. Within 27 different samples and 16 designs, while the highest unconfined compressive strength (mean 24,66 MPa, 28 days) was obtained in the sample containing 10% SD and 1% HP, the highest unconfined compressive strength (mean 25,83 MPa, 56 days) was obtained in the sample containing 20% SD, 10% FA and 2% HP, the highest unconfined compressive strength (mean 24,66 MPa, 28 days) was obtained in the sample containing 10% SD and 1% HP, the highest unconfined compressive strength (mean 26,72 MPa, JG columns) was obtained in the sample containing 10% SD, 10% FA and 1% HP in 81 different samples. While In the short term (28 days) silica fume was increased strength fast, in the long term (56 days) samples and columns containing fly ash was gained late strength