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

2019 ◽  
Vol 3 (3) ◽  
pp. 55-68
Author(s):  
Ali Ajwad ◽  
Abdullah ◽  
Muhammad Usman ◽  
Shakir Ahmad ◽  
Usman Ilyas ◽  
...  

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.

2019 ◽  
Vol 7 (1) ◽  
pp. 24-29
Author(s):  
A. Ajwad ◽  
N. Khadim ◽  
Abdullah ◽  
U. Ilyas ◽  
M. U. Rashid ◽  
...  

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.


2019 ◽  
Vol 3 (2) ◽  
pp. 81-89
Author(s):  
Angga Pirman Firdaus ◽  
Jonbi

Indonesia ranks second in the world's largest plastic waste producer after China. Each year, Indonesia can contributeup to 187.2 million tons of plastic waste, while China reaches 262.9 million tons of plastic waste. Based on the data, one way to utilize plastic waste by using plastic waste as a mixture of concrete, where the plastic used is polypropylene (PP) plastic with different percentage of concrete mixture, the test includes compressive strength test and tensile concrete. The results of concrete compressive strength testing with polypropylene (PP) plastic waste mixture of 5%, 10% and 15% at age 28 in aggregate aggregate mixture decreased by 5.15%, 6.89% and 13.53%. As for the result of concrete tensile strength test with polypropylene (PP) plastic waste mixture of 5%, 10% and 15% at age 28 in crude aggregate mixture decreased 17,61%, 24,13% dan 23,24%.


2019 ◽  
Vol 801 ◽  
pp. 436-441
Author(s):  
Shin Jen Chen ◽  
Chao Shi Chen ◽  
Jyun Yong Jhan ◽  
Ruei Fu Chen

Controlled low-strength materials (CLSM) have begun to apply in a lot of countries because CLSM could distribute randomly in complex sites. Manufacturing from chlor-alkali industry, the brine sludge was used to replace the composition in CLSM for resource application. In this study, the mix composition of brine sludge replaced only the fine aggregates or all of the aggregates. Examining the suitable composition, the ball drop test and the compressive strength test were carried out. The ball drop test was applied to determine the readiness of the CLSM to accept loads prior, and the bearing capacity at different ages were measured by the compressive strength test. The results of the ball drop test in different replacements was 7 - 11.5 cm. The replacement of fine aggregates satisified the rule of CLSM. Replacing all of the aggregates, the mixtures were over 7.6 cm, which meant that the early strength at 1 day were not sufficient. The value of compressive strength at 28 days was 1.709 - 21.37 kgf/cm2, conforming the requirement of CLSM. Overall, the mixture which replaced the fine aggregates met all the specified values of CLSM. In particular, the composition of coarse aggregates reduce to 250 kg/m3, the utalization of the brine sludge could be the most.


2019 ◽  
Vol 9 (1) ◽  
pp. 15-22
Author(s):  
Era Rizky Hasanah ◽  
Agustin Gunawan ◽  
Yuzuar Afrizal

Concrete has a high compressive strength, but it is low to tensile strength. The pinang skin fiber and wood powderuse to increase the tensile strength. The purpose of this research is to know the effect of addition toward tensile strength and addition percentage variation in concrete that will get the highest tensile strength.The cylindrical specimens with size of 30 cm high and 15 cm diameter to 20 specimens, they are 4 sample of normal concrete and 16 sample of variation oncrete. The addition of pinang skin fiber and wood powder with variation of 0.25%, 0.5%, 0.75%, and 1% of the weight volume of the specimen with used 50% pinang skin fiber and 50% wood powder.The mixture of concrete uses water cement ratioof 0.5 and 60-100 mm slump.The test specimen is immersed for 26 days and the concrete tensile strength test conducted after the concrete at 28 days adding 7 days for drying.The result of this research shows that the variation concrete of 0.25% and 0.5% have increased of tensile strength than the normal concrete as 12.272% and 4.369%. Beside that for the variation concrete of 0.75% and 1% have decreased as 5.044% and 11.929%. The increase of tensile strength value of optimal concrete is found in variation 0.25% that is 12.272% from normal concrete.


Conventional cement based composites have constituent materials such as Portland cement, supplementary cementitious materials, fine sand, super-plasticizer and water. To achieve high performance, these composites needs high cement content in it which will cause high cost of production. Addition of supplementary cementitious materials as partial substitutes for cement will help in reducing the cost. In this study, a pre-characterized mix proportion of cementitious composite, in which 30% of cement was substituted with lime powder. To enhance the ductility of the composite, the matrix is reinforced with 2% (by volume of composite) of crimped steel fibres. Further, hybridisation of metallic and non-metallic fibres is done in this study to bring the self-weight of the mix down and to reduce the chances of degradation due to the corrosion of fibres. Fibre hybridisation was done by replacing 25%, 50%, 75% and 100% by volume of steel fibres with poly propylene (PP) fibres. The characterisation of the fibre reinforced composites was done by assessing their workability by conducting flow test, compressive strength test, split tensile strength test, flexure test and low velocity impact test. It was observed that, the mix with 100% of steel fibres replaced with PP fibres exhibited better workability. It was also observed that, compressive strength, split tensile strength, modulus of rupture and impact resistance were maximum for the mix reinforced with steel fibre alone and the strengths got reduced gradually due to hybridisation of fibres. Based on the requirement of strength, a combination of steel and PP fibres can be used for reinforcing the matrix, which will help in improving ductility, reducing self-weight. By this, the matrix can be made more resistant to corrosion and can be used in structures especially in the marine environment.


2018 ◽  
Author(s):  
Erniati Bachtiar

Concrete construction technology is directed to be sustainable and ecofriendly. The waste of the candlenut shell as a substitute for the coarse aggregate of concrete mixture is known that the candlenut shell has a hard texture so it may be used as a substitute for coarse aggregates in concrete. The purpose of the research was to determine the effect of Candlenut shell as a substitute of coarse aggregate on physical properties (slump test, bleeding, segregation, volume weight) and mechanical properties (compressive strength and tensile strength) of concrete using Candlenut shell as replacement material of the coarse aggregate. The variation of the research was percentage of the Candlenut shell in the concrete mixture, that was 0%, 25%, 50%, 75% and 100% to the coarse aggregate volume in the concrete mixture. Number of specimens in reseach was each 5 pieces each variation. Testing of mechanical properties of concrete (compressive strength and tensile strength) was performed at 28 days. Testing of the concrete for compressive strength test and tensile strength on age 28 days. Concrete using candlenut shell as a substitute of coarse aggregates has decreased compressive strength respectively 11.72 MPa (37.71%) for 25% candlenut shell; 15.54 MPa (50.00%) for 50% candlenut shell; 18.35 MPa (59.02%) for 75% candlenut shell; And 18,85 MPa (60,66%) for 100% candlenut shell from of the 0% candlenut shell with compressive strength of 31.08 Mpa. Concrete using for 25% candlenut shell as a substitute for coarse aggregates decreased tensile strength respectively of 0.95 MPa (28.70%) for 25% candlenut shell; 1.21 MPa (36.56%) for 50% candlenut shell; 1.27 MPa (38.37%) for 75% candlenut shell; And 1.40 MPa (42.30%) for 100% candlenut shell from of the 0% candlenut shell with the tensile strength of BN of 3.31 MPa. The decrease in the value of compressive strength and tensile strength is strongly influenced by the increasing percentage of Candlenut shells on concrete


2020 ◽  
Vol 39 (3) ◽  
pp. 710-720
Author(s):  
I.M. Adamu ◽  
J.M. Kaura ◽  
A. Lawan ◽  
A. Ocholi

The failure of conventional concrete to have classical mechanical properties, reduced permeability and lead to sustainability in concrete production called for the use of supplementary Cementitious Materials (SCM) in concrete to improve its performance. This study investigates the effect of adding optimal dosage of an SCM called nanosilica (nS) on the tensile and compressive strengths, microstructural properties and cement hydration reaction for grade 30 concrete. The optimal dosage of the nS was determined to be 1.5% by weight of cement using compressive strength test. The influence of optimal nS dosage on the concrete properties was investigated using compressive strength test, splitting tensile strength test, Scanning Electron Microscopy (SEM) and Energy Dispersion Spectroscopy (EDS). Results revealed that optimal nS addition led to 30% and 23.3% respective increase in compressive and tensile strengths of conventional concrete at 7days of curing. SEM micrographs show better packing density in the nano-concrete at 90days of curing. EDS shows that addition of optimal nS dosage in concrete led to formation of more C-S-H gels at 90days curing period, and a corresponding reduction in Ca/Si ratio of the nano-concrete to 0.89; a ratio that is very close to that of 14Ǻ tobermorite reported in literature. The optimal nano-concrete can be used where strength improvement, especially at early age and reduction in concrete permeability are requirements. Keywords: Compressive strength, Tensile strength, Normal strength nano-concrete, SEM, EDS.


2018 ◽  
Author(s):  
erniati

Self Compacting Concrete (SCC) is one solution to get concrete construction which it has good resistance. Durability of concrete was obtained by the good concrete compaction to be done by a skilled workforce. However, one of the negligence that often occur in the field ie after casting they was ignoring curing of the hardening concrete. This study discusses the workability of fresh concrete and mechanical properties (compressive strength and splitting tensile strength) on SCC without curing. Testing of the concrete workability based on EFNARC standard. The mechanical properties test based on ASTM standards. The method Compressive strength test based on ASTM standards 39 / C 39M - 12a, whereas splitting tensile strength accordance standard ASTM C496 / C496M-11. The results of the study indicate that the SCC without curing effect on the reduction in compressive strength at ages 1, 3, 7, 28, and 90 days in a row at 4.11 MPa (16.1%); 4.90 MPa (13.9%); 6.64 MPa (13.1%); and 6, 72 MPa (12.75%). Splitting tensile strength decreased respectively by 0.1 MPa (3.25%); 0.26 MPa (7.99%); 0.4 MPa (9.52%); and 0.39 MPa (9.16%).


2019 ◽  
Vol 8 (3) ◽  
pp. 7736-7739 ◽  

This paper studies the effect of incorporating metakaolin on the mechanical properties of high grade concrete. Three different metakaolins calcined at different temperature and durations were used to make concrete specimens. Three different concrete mixtures were characterized using 20% metakaolin in place of cement. A normal concrete mix was also made for comparison purpose. The compressive strength test, split tensile test and flexural strength tests were conducted on the specimens. The compressive strength test results showed that all the metakaolin incorporated concrete specimens exhibited higher compressive strength and performed better than normal concrete at all the days of curing. The rate of strength development of all the mixes was also studied. The study revealed that all the three different metakaolin incorporated mixtures had different rate of strength development for all the days of hydration (3, 7,14, 28, 56 and 90), indicating that all the metakaolins possessed different rate of pozzolanic reactivity. Further, from the analysis of the test results, it was concluded that the variation in the rate of strength development is due to the differences in the temperature and duration at which they were manufactured. The results of split tensile strength test and the flexural strength test conducted on the specimens, supported the conclusions drawn from the results of compressive strength test. The paper also discusses, the rate of development of compressive strength and the pozzolanic behaviour of the metakaolins in light of their parameters of calcination and physical properties such as amorphousness and particle size. This paper has been written with a view to make the potential of metakaolin available to the construction industry at large


Author(s):  
S. B. Kandekar ◽  
◽  
S. K. Wakchaure ◽  

Materials are the most important component of building construction. The demands of construction material are increasing day by day significantly. This demand is increasing the material prices and scarcity of material in construction industry. To achieve economical and eco-friendly criteria naturally occurring material is selected. Clay is a natural material and it can be available easily. This paper interprets the experimental investigation on strength of concrete using clay as a partial replacement to binder content (cement) in concrete. The replacement percentages are grouped as 0%, 10%, 20%, 30%, 40% of clay and 5% of hydrated lime with cement in each series in M25 grade of concrete. To achieve the pozzolanic property of clay hydrated lime was added. Different tests are performed to determine the optimum percentage of clay as a replacement for binder content (cement) in concrete. The Compressive strength test, split tensile strength test and flexural strength test were performed on the specimens. Total 90 cubes of size 150 mm were prepared for compressive strength test, 30 cylinders of 150 mm diameter and 300 mm height were prepared for split tensile strength test and 30 beams of size 150 mm x 150 mm x 1000 mm were prepared to carry out the flexural strength test. The results are compared to find the ideal proportion of clay as a replacement for cement. It is found that 10% replacement with 5% hydrated lime gives satisfactory results.


Sign in / Sign up

Export Citation Format

Share Document