Comparison of Red Mud with Flyash for Its Utilization as a Geotechnical Material

Transcription

1 Comparison of Red Mud with for Its Utilization as a Geotechnical Material Er. Lovedeep Singh Post graduate Geotechnical Engineer (M.tech from Guru Nanak Dev Engineering College, Ludhiana, Punjab) Er. Shahbaz Singh Post graduate Geotechnical Engineer, (M.tech from Guru Nanak Dev Engineering College, Ludhiana, Punjab) ABSTRACT- Waste generation is an inevitable part of all the human activities especially the day to day industrial activities that are carried out for the development and growth of mankind. These industrial waste products however can be re-used. Reuse of the industrial wastes has many applications in different areas. In this study two industrial wastes flyash and red mud have been compared for their applicability in geotechnical engineering. The geotechnical properties of red mud and flyash have been determined and compared. has been used for comparison because of its exclusive and extensive application in the construction industry in different branches of civil engineering. The test results reveal that has an equal potential as flyash to be used as a geotechnical material. The high dry density of 18kN/m 3, UCS value of 98 kpa and soaked CBR value of 4.74% make red mud an ideal construction material in embankments, road sub-grade and sub-base and fill material in earth retaining structures such as bridge abutments and retaining walls. Keywords-California bearing ratio (CBR), Unconfined compres sive strength (UCS),,, Optimum moisture content (OMC), Maximum dry density (MDD) INTRODUCTION Waste is generated in every process cycle either in the industry or our normal routine life. Due to high consumption of natural resources for the industry by the humans the impact of waste generation on the environment is becoming adverse by the passing time. Industrial waste is generated in large quantities and left in open and disposed off without any treatment. But these waste products can be a resource for some other purposes and applications. One such waste is flyash, which has been used in construction industry from past couple of decades especially in cement industry by the name of Pozzolana Portland Cement and in soil stabilization in the field of geotechnical engineering. Figure 1 disposal at NALCO, Damanjodi, Odisha 314 Er. Lovedeep Singh, Er. Shahbaz Singh

2 From the past few decades flyash has been highly used as a geotechnical material particularly in embankments and pavement construction layers such as base and sub-base layers and in cement and concrete production. which is another industrial waste that is produced during the extraction of aluminium from bauxite is also a hostile material to the environment as it is a major soil and underground water pollutant. is generally disposed off as a dry, semi dry in red mud pond in the form of slurry. In India there are 5 major public sector aluminium extraction plants which produce approximately 5.5 million tons of red mud. There is a lot of study carried out on possible applications of red mud in different sectors but till date no practically viable and environmental friendly application of red mud has been observed. In this study an attempt has been made to check the possibility of application of red mud in geotechnical engineering by comparing the geotechnical properties of red mud with that of flyash which is being extensively used in civil engineering these days. The red mud for this study was collected from NALCO, Damanjodi, Odisha and flyash was collected from GGSS Thermal Power Plant, Ropar, Punjab. Following properties of both the materials were determined experimentally and then compared Specific gravity Particle size analysis Maximum dry density and Optimum moisture content Unconfined compressive strength CBR value EXPERIMENTAL RESULTS Specific gravity The specific gravity of flyash was reported to be 2.2 and that of red mud was 2.67 after conducting Pycnometer test on both the samples. So, in comparison to flyash red mud has higher value of specific gravity which is a direct indicator of the strength of red mud. Particle size analysis Sieve analysis on fly ash and red mud was conducted and following are the gradation curves of both the samples. 1 Percentage Finer (%) Particle size (mm) 315 Er. Lovedeep Singh, Er. Shahbaz Singh Figure 2 Gradation curves of and

3 It is clear from the above figure that red mud has more range of particles than fly ash. The co-efficient of uniformity of red mud was reported to be 24, which indicates that red mud has a wider range of particles of different sizes. Standard proctor test Standard proctor test is conducted to determine the maximum dry density and optimum moisture content. The test results showed that the optimum moisture content and maximum dry density of flyash were 32% and 1.3 kn/m 3 respectively and for red mud the parameters were 18% and 18.17kN/m 3 respectively. Dry Density ( kn/m 3 ) Moisture content (%) Figure 3 OMC v/s Dry density plot of red mud and flyash It is clear from the above result representation that there is more flocculation of the particles of flyash which may be responsible for higher moisture content and a lesser dry density. Unconfined compressive strength test- Following are the test results of UCS test. Unconfined compressive strength (kpa) Curing period (No. of days) Figure 4 UCS test results of red mud and flyash The test was carried out for different samples at different curing period of 1 day, 7 days, 21 days and 28 days. The test results showed that at 28 days curing period the unconfined compressive strength of flyash was reported to 85 kpa and strength of red mud was 98kPa. 316 Er. Lovedeep Singh, Er. Shahbaz Singh

4 California bearing ratio test The CBR test was conducted on the samples of red mud and flyash after 96 hrs of soaking period to simulate the worst field conditions. Following is the representation of observations made during the test. Load (kg) Penetration (mm) Figure 5 Load v/s Penetration curves of CBR test for red mud and flyash The load v/s penetration curves clearly indicate that the CBR value of red mud is more as compared to flyash. The CBR value of red mud was reported to be 4.74% and that of fly ash was reported to be 3.64% Geotechnical properties- The test results obtained for both the materials have been compared in tabulated form as follows- Table 1 Geotechnical properties of red mud and flyash S.No. Parameter 1. Specific gravity Optimum moisture content (%) Maximum dry density (kn/m 3 ) UCS value (kpa) CBR value soaked (%) CONCLUSIONS - From the obtained test results it can be concluded that the geotechnical properties of red mud are comparable to flyash. The higher value of specific gravity and dry density account for its feasibility to be used as a fill material in earth retaining structures such as bridge abutments and retaining walls. It is evident from the UCS test results that red mud can also be used as a highway embankment material and from CBR test results it can be concluded that red mud can be potentially used as a base and sub-base material. The potential use of red mud as a soil stabilizer can also be investigated. 317 Er. Lovedeep Singh, Er. Shahbaz Singh

5 REFERENCES 1. Cabllk, V. (7). Characterization and applications of red mud from bauxite processing. The British Library the World s Knowlege, Haque, M. E. (13). Indian Fly -Ash: Production and Consumption Scenario. International Journal of Waste Resources, 3(1), Nawaz, I. (13). Disposal and Utilization of Fly Ash to Protect the Environment. International Journal of Innovative Research in Science, Engineering and Technology, 2(1), Patel, S., & Pal, B. K. (15). Current Status of an Industrial Waste : Red Mud an Overview, IV(Viii), Santos, F., Li, L., Li, Y., & Amini, F. (11). Geotechnical Properties of Fly Ash and Soil Mixtures for Use in Highway Embankments. 6. Singh, R. R., Goyal, N., & Kaur, N. (15). Fly ash as an embankment material. SSRG International Journal of Civil Engineering, 2(3), Sutar, H., Mishra, S. C., Sahoo, S. K., Prasad, A., & Maharana, H. S. (14). Progress of Red Mud Utilization : An Overview. American Chemical Science Journal, 4(3), Er. Lovedeep Singh, Er. Shahbaz Singh