scholarly journals Enhancing the Flexural Strength of Concrete using Recycled Iron and Steel Slag Aggregate

Author(s):  
A. A Raheem

Concrete is strong in compression but weak in tension hence, considerable effort is required to improve concrete’s tensile strength by the use of pre-stressed concrete and addition of admixtures or additives. In this study, the use of recycled iron and steel slag (RISS) aggregate to improve the tensile strength of concrete was considered. The paper assessed the mineralogical composition of RISS and granite aggregates, and gradation. It also determines the effects of RISS aggregate on the flexural strength of concrete beams of 150 × 150 × 600 mm containing 0, 10, 20, 40 and 60% RISS aggregate replacement in mix ratios 1:1½:3, 1:2:4 and 1:3:6 with water cement ratios 0.65,0.60 and 0.55 respectively. Diffractograph of RISS and granite aggregate showed that RISS contains Magnetite, Ilmenite and Quartz, while granite contains Quartz, Annite, Microcline and Albite as the predominant minerals. The coefficient of uniformity and concavity of RISS and granite aggregate for maximum aggregate size of 37.5 mm are 4.35 and 1.33; and 4.64 and 1.76 respectively. Both aggregates contain quartz as the predominant mineral and are well graded. The result of the Flexural strength at 28 days curing is within 0.135 – 0.250 MPa specified byBS8500 – 2:2015. Flexural strength of concrete beams cast with RISS aggregate is relatively higher than concrete cast with granite aggregate. Flexural strength, a measure of tensile strength of concrete is improved as percentage RISS aggregate increased.

2014 ◽  
Vol 13 (4) ◽  
pp. 137-144
Author(s):  
Małgorzata Konopska-Piechurska ◽  
Wioletta Jackiewicz-Rek ◽  
Paweł Łukowski

In the paper the results of experiments on concrete pavement with exposed aggregate technology placed in two technological layers were presented. The following properties were measured: compressive strength, flexural strength by two methods: two-point loading and centre-point loading, tensile splitting strength of cubic and cylindrical samples. The study was performed for two type of concrete with a maximum aggregate size Dmax 8 mm (concrete applied to the upper layer of concrete pavement - GWB) and Dmax 22 mm (concrete used for the bottom layer - DWB). After the analysis of the tests, the correlations between compressive strength and tensile strength, measured by flexural strength and tensile splitting strength, were determined for the used two-layers concrete pavement with exposed aggregate depending on applied Dmax.


The present Investigation is aimed at utilizing low cost material Dolomite powder and waste material Quarry dust as partial replacement of cement and sand in concrete. This experimental investigation is carried out in three stages. In 1st stage M25 grade of concrete is produced by replacing cement by 0%, 6%, 12% and 18% of Dolomite Powder. In 2nd Stage concrete is produced by keeping the optimum 12% of dolomite powder as constant and sand is replaced by quarry dust in the percentage of 0%, 25%, 35% and 45%. In 3rd stage the optimum percentage of Dolomite Powder and Quarry Dust (DP+QD) Concrete are used to determine the compressive strength, split tensile strength and flexural strength of concrete and to check the flexural behavior of RCC beams. It is found that the concrete made of low cost material dolomite powder and waste material quarry dust increases the compressive strength, split tensile strength and flexural strength of concrete when compared to that of normal concrete. It also concluded that the first crack load and ultimate load of dolomite powder and quarry dust reinforced concrete beams increases when compared with normal reinforced concrete beams. From study it is concluded that the low cost material Dolomite powder & Quarry dust can be used in construction works which results in construction cost. By using natural resources the environment is protected.


Author(s):  
Solomon I. Adedokun ◽  
Mukaila A. Anifowose

Steel is produced from iron ore and purification of metal scrap, leading to manufacture of hundreds of tonnes of steel slag each year. This study investigated the optimum replacement of granite with Ife Iron and Steel Nigeria Limited (ISN) slag that produce maximum Compressive Strength (CS), Split Tensile Strength (STS) and Flexural Strength (FS) of concrete using Response Surface Methodology (RSM) from Design Expert Version 7.0. The outcome of the study showed that the optimum replacement of granite with ISN was 28.85% ISN at 0.47 W/C.


2021 ◽  
Vol 3 (3) ◽  
pp. 448-458
Author(s):  
Anisa Tikupadang ◽  
Herman Parung ◽  
Benny Kusuma

Steel slag is a waste from the steel smelting industry. Along with the increasing demand for steel, it can also cause steel waste to increase. Coconut shell is a solid waste from the rest of coconut processing. This study aims to obtain the compressive strength, split tensile strength, flexural strength, and modulus of elasticity with coarse aggregate substituted for steel slag and coconut shell, with a concrete quality of f'c 45 MPa. The results of this study that the compressive strength of concrete obtained, 100% crushed stone aggregate increased 5.213% and coconut shell substitution and steel slag increased 1.650%. The value of the split tensile strength of concrete, 100% crushed stone is 9.312% and the substitution of coconut shells and steel slag is 9.073 of the compressive strength. The value of flexural strength, 100% crushed stone is 0.827√(f'c) and the substitution of coconut shell and steel slag is 0.752 f'c from the compressive strength. The modulus of elasticity of concrete, 100% crushed stone is 24845,351 MPa and substitution of coconut shells and steel slag is 20674,005 MPa.    


2019 ◽  
Vol 27 (1) ◽  
pp. 382-395
Author(s):  
Mousa Zeki ◽  
Shakir Al-Busaltan

Statistical modeling is utilized effectively to development relation/s between the dependent variables and independent variables. In other words, it describes how one or more random variables are related to one more other variables. Building verified models can help in predicting performance characteristics, and saving time and money. This study aims to present a statistical models which help to understand the significance of the different parameters in characterizing the performance of the Thin Asphalt Overlay (TAO). The experimental program included: design the thin asphalt overlay mixtures using one gradation type (9.5 Nominal Maximum Aggregate Size NMAS), three filler types (conventional mineral filler, Ordinary Portland Cement, and Quick lime), and five percentages of asphalt content to identify the optimum asphalt content. Then, Styrene Butadiene Styrene (SBS) modified polymer binder was introduced for performance enhancement. Performance tests were used to evaluate TAO mixture in term of some main namely, volumetric, mechanical, and durability properties are (bulk density, indirect tensile strength and tensile strength ratio). Statistical Product and Service Solutions (SPSS) software (Version 24) was used as a tool for models building. To find the most accurate statistical models, linear and nonlinear regression was achieved. This study demonstrates that the using statistical modeling is achievable and offer a vital tool to describe the characteristics and performance of the TAO mixture in term volumetric, mechanical and durability properties.


2020 ◽  
Vol 26 (5) ◽  
pp. 172-190
Author(s):  
Shubbar Jawad Al-obaidey

The main objectives of this study were investigating the effects of the maximum size of coarse Attapulgite aggregate and micro steel fiber content on fresh and some mechanical properties of steel fibers reinforced lightweight self-compacting concrete (SFLWSCC). Two series of mixes were used depending on maximum aggregate size (12.5 and 19) mm, for each series three different steel fibers content were used (0.5 %, 1%, and 1.5%). To evaluate the fresh properties, tests of slump flow, T500 mm, V funnel time, and J ring were carried out. Tests of compressive strength, splitting tensile strength, flexural tensile strength, and calculated equilibrium density were done to evaluate mechanical properties. For reference mixes, the results showed that mixes with a larger maximum aggregate size of 19 mm exhibited better fresh properties, while mechanical properties negatively affected by using a larger maximum aggregate size. The results also showed that using steel fibers led to negative effects on fresh properties, especially with higher steel fibers content and larger maximum aggregate size. The marginal effect of steel fibers on compressive strength was noticed, while for both splitting and flexural tensile strength, significant increase was obtained with increasing of steel fibers content. The properties of SFLWSCC in the fresh state had a considerable effect on mechanical properties, whereas with the best fresh properties, the best mechanical properties can be obtained.


2021 ◽  
Vol 107 ◽  
pp. 97-112
Author(s):  
Akeem Ayinde Raheem ◽  
Oluwaleke A. Olowu ◽  
Anthony Ajibola Hungbo ◽  
Emmanuel Olatunde Ibiwoye

Effects of Water cement ratios on strengths characteristics of concrete produced with Recycled Iron and Steel Slag (RISS) aggregates was studied to understand the structural integrity of RISS aggregate in concrete and to determine the veracity of RISS aggregate as alternative aggregate to granite in concrete works. Mineralogical composition of the aggregate showed Silicon oxide (quartz) as the common mineral; both aggregates are well graded, strong and durable. Lower water cement ratios improved both the compressive and flexural strengths of RISS and granite concrete.


2018 ◽  
Vol 8 (3) ◽  
pp. 2892-2896
Author(s):  
S. Iqbal ◽  
N. Ullah ◽  
A. Ali

The bond between reinforcements and concrete is the only mechanism that transfers the tensile stresses from concrete to reinforcements. Several factors including chemical adhesion, roughness and reinforcement interface and bar bearing affect the bond strength of reinforcements with concrete. This work was carried out considering another varying factor which is maximum aggregate size. Four mixes of concrete with similar compressive strengths but different maximum aggregate sizes of 25.4mm, 19.05mm, 12.7mm and 9.53mm were used with the same bar size of 16mm. Compressive strength, splitting tensile strength and bond strength for each concrete mix were studied. Test results depict a slight increase in compressive and splitting tensile strength with decrease in maximum aggregate size. The bond strength remained at the same level with decrease in maximum aggregate size except at maximum aggregate size of 9.53mm when there was a drop in bond strength, despite better compressive and splitting tensile strengths. ACI-318 and FIB-2010 codes equation for bond strength calculation work well only when the maximum aggregate size is 12.7mm and above. Therefore, maximum aggregate size is critical for bond strength when smaller size aggregates are used.


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