Plasticity and Strength Behaviour of Marine Clay Stabilized with Waste Steel Dust for Soil Improvement Works

Soft marine clay soil is characterized with highly compressible behavior, in which associated with poor bearing capacity and low in shear resistance. Soil improvement works are carried out to reduce the soil failure and destruction to the superstructure. Various techniques available for soil stabilization including the use of admixture to improve the engineering properties of the problematic soil. This paper aims to report on the use of waste steel dust retrieved from the medication supply industry as soil stabilization agent. Several series of Atterberg limit test and Unconfined Compressive Test were carried out to foresee the potential use of the waste steel dust for the purpose of civil engineering applications. The significant findings from this study is evident that the waste steel dust ranges from 5% to 15% did not able to serve as soil stabilization agent. It can reduce the plastic behavior of the soil sample; however, it also caused the strength of the soil declined. In comparison with previous studies, the presence of activated agent could possibly enhance the performance of waste steel dust as an alternative treatment agent to soil improvement works. The use of activated agent is to serve as pozzolanic materials to create cementitious bonding in between the soil interparticles matrix.

Effect of Mixing Steel Dust and Shred-Like Steel Fibres on the Properties of Concrete

In this research, fine and coarse aggregates present in the concrete are replaced with steel dust and shred-like steel fibres, respectively in different ratios and its effect on the properties of concrete is studied. Eight batches of concrete were mixed, each with the mix proportion of 1:2:4 and water cement ratio of 0.52. Batch A was of normal concrete. In batches B, C, and D, 5%, 10%, and 15% of sand was replaced with steel dust. In batches, E, F, and G, 2%, 5%, and 8% of coarse aggregate were replaced with steel fibres. In the last batch H, both 5% of sand and 5% of coarse aggregate were replaced with steel fine and steel fibres respectively. British as well as American standards were followed during the research. Slump test was performed in a fresh state of each mix to find the effect of these replacements on workability. 12 cubes of 150mm x 150mm x 150mm for compressive strength test and 12 cylinders of 150mm diameter and 300mm height of each, for tensile strength test were made for each batch to check these strength after 3, 7, 14, 28 days. It was found that the workability of fresh concrete decreases while density of fresh as well as hardened concrete increases with these replacements. It also results in an increase in initial compressive strength and a decrease in final compressive strength as compared to those of normal concrete. As far as tensile strength is concerned an increase in initial as well as final strength was observed.

Development of Asbestos-free Brake Pads Using Bamboo Leaves

Asbestos-based brake pads are not desirable due to the carcinogenic nature of asbestos. Organic asbestos-free brake automotive brake pad produced from bamboo leaves was evaluated in this study. Ground bamboo leaves were sieved into sieve grades of 100, 200, and 350 μm. The sieved bamboo leaves particles were then combined with 15 % steel dust, 10% graphite, 20% resin, Silicon Carbide varied five (5) times between 35-55 % and 0-20% respectively for each sieve grade to make brake pads of different ratios. The mechanical properties (hardness, compressive strength, density, porosity, wear rate, and flame resistance) of the produced samples were investigated. The results showed that the finer the particle size of the bamboo leaves, the better the mechanical properties of the produced samples. The results of this work when compared with those of the commercial (asbestos based) brake pad showed they were in close agreement except for the wear rate and porosity property. Therefore, bamboo leaves could be used in the production of asbestos free brake pads if the wear rate and porosity properties of the produced samples could be improved.

Enhancing Concrete Properties by Adding Shred-like Steel Fibres and Steel Dust

In this research, fine and coarse aggregates present in the concrete were replaced with steel dust and shred-like steel fibres respectively in different ratios and the effect of their replacement on the properties of concrete was studied. Eight batches of concrete were mixed, each with the mix proportion of 1:2:4 and water- cement ratio of 0.52. Batch A was of normal concrete. In batches B, C, and D, 5%, 10%, and 15% of sand was replaced with steel dust, respectively. In batches, E, F, and G, 2%, 5%, and 8% of coarse aggregates were replaced with steel fibres. In the last batch H, 5% of sand and 5% of coarse aggregates were replaced with steel fines and steel fibres, respectively. British as well as American standards were followed during the research. Slump test was performed in the fresh state of each mix to find the effect of these replacements on its workability. 12 cubes of 150mm × 150mm × 150mm for compressive strength test and 12 cylinders of 150mm diameter and 300mm height for tensile strength test were made for each batch to check their strength after every 3, 7, 14, and 28 days. It was found that the workability of fresh concrete decreases while the density of fresh as well as hardened concrete increases with these replacements. They also result in an increase in initial compressive strength and a decrease in final compressive strength as compared to those of normal concrete. As far as tensile strength is concerned, an increase in initial as well as final strength was observed.