scholarly journals Effect of Locally Available Wheat Straw Ash in Developing High Strength Concrete

Author(s):  
Muhammad Armaghan Siffat ◽  
Muhammad Ishfaq ◽  
Afaq Ahmad ◽  
Khalil Ur Rehman ◽  
Fawad Ahmad

This study is supervised to assess the characteristics of the locally available wheat straw ash (WSA) to consume as a substitute to the cement and support in enhancing the mechanical properties of concrete. Initially, after incineration at optimum temperature of 800°C for 0.5, the ash of wheat straw was made up to the desirable level of fineness by passing through it to the several grinding cycles. Subsequently, the X-ray fluorescence (XRF) along with X-ray diffraction (XRD) testing conducted on ash of wheat straw for the evaluation its pozzolanic potential. Finally, the specimens of concrete were made by consuming 10% and 20% percentages of wheat straw ash as a replacement in concrete to conclude its impact on the compressive strength of high strength concrete. The cylinders of steel of dimensions 10cm diameter x 20cm depth were acquired to evaluate the compressive strength of high strength concrete. The relative outcomes of cylinders made of wheat straw ash substitution presented the slight increase in strength values of the concrete. Ultimately, the C-100 blends and WSA aided cement blends were inspected for the rheology of WSA through FTIR spectroscopy along with Thermogravimetric technique. The conclusions authenticate the WSA potential to replace cement in the manufacturing of the high strength concrete.

2020 ◽  
Vol 38 (2A) ◽  
pp. 173-184 ◽  
Author(s):  
Saman M. Kamal ◽  
Jalal A. Saeed ◽  
Ahmed Mohammed

One of the main challenges facing Civil Engineering community is to modify cement quantity in the mix design by admixtures to enhance the mechanical properties. According to more than 1000 data from literature, mechanical characteristics of concrete modified with FA were discussed. The statistical variation with modeling were achieved by set of data. The cement was replaced up to 70% with FA (weight of dry cement) and by cube of concrete testing up to 90 days of curing time and different w/c ratio. The compressive strength of concrete varied from 18-67 MPa, while, for modified concrete with FA, compressive strength ranged from 21-94 MPa, tensile strength ranged from 1-9 MPa and flexural strengths ranged from 3 - 10 MPa. The w/c ratio of concrete modified with FA varied from 0.24-0.53, also the FA content varied from 0-50 %. Vipulanandan correlation model was effective by connecting mechanical properties and compare with Hoek-Brown model. The nonlinear model was used to investigate the effect of FA on properties of normal and high strength concrete. Study results presented a worthy correlation between compressive strength and curing time, w/c ratio and FA content. By using the interactive linked (model) for compressive, tensile, and flexural strengths of concrete quantified well as a function of w/c ratio, curing time and FA content by using a nonlinear relationship.


2012 ◽  
Vol 472-475 ◽  
pp. 1119-1125 ◽  
Author(s):  
Ke Feng Tan ◽  
Lai Bao Liu

This study investigated the mechanical properties of High Strength Concrete filled steel tubular short columns (HSCFSTSC) with length to diameter ratio (L/D) of 3.5.The strength of concrete used to fill the steel tubular columns ranged from 54MPa to 116MPa. The test results showed that using a steel tube as confinement can significantly improve the ductility and compressive strength of core concrete. The magnitude of compressive strength increase of core concrete was directly proportional to the Confinement Index, , and the extent of improvement of the ductility increases as the  increases. For thoroughly improving the ductility of core concrete, the Confinement Index  should be equal or larger than 0.48. The formula used to calculate the load bearing capacity of HSCFSTSC was given out.


Author(s):  
Muhammad Ishfaq ◽  
Akhtar Gul ◽  
Malik Hammad Naseer

This study examines the effects of different burning temperature on the chemical and microstructure properties of WSA. In many parts of the world due to non-availability of proper technology, the farmers generally burn wheat straw after acquiring grains, which causing environmental pollution with fire hazards at farm level and loss valuable commodity. In this research, the influence of different temperature on locally available Wheat Straw in Province KP, Pakistan was study. This research aim to find optimum temperature and burning duration of WSA by examine chemical and microstructural properties of WSA at 550oC for 4 hr, 550oC for 8 hr and 800oC for 30 min. The tests results were categorized through X-ray Diffraction (XRD), X-Ray fluorescence (XRF) and Fourier Transform Infrared Spectroscopy (FTIR). The result showing the 550oC for 4 hr contains high amount of (SiO2+Al2O3+Fe2O3) and amorphous nature as compared to other samples.


2012 ◽  
Vol 174-177 ◽  
pp. 1388-1393
Author(s):  
Hai Qing Song ◽  
Teng Long Zheng

Plain concrete is susceptible to cracking under aggressive environment such as in freezing shaft. And addition of steel fibres in plain high strength concrete is proved to be effective in cracking resistance and brittleness improvement, etc. This paper presents results of experimental investigation carried out to study the mechanical properties of steel fibre-reinforced concrete having volume fractions of 0.38%, 0.51% and 0.64% for two types of fibres respectively. The results of this study revealed that there is an increase for all the mechanical properties such as compressive strength, split tensile strength, modulus of elasticity and flexural strength. Enhancement for split tensile strength and flexural strength is more evident than compressive strength.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Neno Torić ◽  
Ivica Boko ◽  
Bernardin Peroš

This paper presents an experimental study of behaviour of high-strength concrete at high temperature. Reduction of the mechanical properties of concrete was determined starting from the period when the concrete specimens were heated to the maximum temperature and cooled down to ambient temperature and the additional 96 hours after the initial cooling of the specimens. The study includes determination of compressive strength, dynamic and secant modulus of elasticity, and stress-strain curves of concrete specimens when exposed to temperature level up to 600°C. The study results were compared with those obtained from other studies, EN 1994-1-2 and EN 1992-1-2. Tests point to the fact that compressive strength of concrete continues to reduce rapidly 96 hours after cooling of the specimens to ambient temperature; therefore indicating that the mechanical properties of concrete have substantial reduction after being exposed to high temperature. The study of the dynamic and secant modulus of elasticity shows that both of the properties are reduced but remain constant during the period of 96 hours after cooling. The level of postfire reduction of compressive strength of the analyzed concrete is substantial and could significantly affect the postfire load bearing capacity of a structure.


2019 ◽  
Vol 9 (2) ◽  
pp. 202-207
Author(s):  
Imad R. Mustafa ◽  
Omar Q. Aziz

An experimental program is carried out to evaluate the mix design and mechanical properties of normal strength concrete (NSC) grade 40 MPa and high-strength concrete grade 60 and 80 MPa. The study investigates using silica fume to produce high-strength concrete grade 80 MPa and highlights the influence of adding steel fiber on the mechanical properties of normal and high-strength concrete. For NSC, the compressive strength is found at 7 and 28 days. While for higher strength concrete, the compressive strength is determined at 7, 28, and 56 days. The splitting tensile strength and flexural strength is determined at 28 days. Based on results, the specimens with 14% silica fume are higher compressive strength than the specimens with 10% silica fume by 21.8%. The presence of steel fiber increased the compressive strength of normal and high-strength concrete at 7, 28, and 56 days curing ages with different percentage and the steel fiber has an important role in increasing the splitting tensile strength and flexural strength of normal and high-strength concrete.


2014 ◽  
Vol 1077 ◽  
pp. 113-117 ◽  
Author(s):  
Filip Vogel ◽  
Ondřej Holčapek ◽  
Marcel Jogl ◽  
Karel Kolář ◽  
Petr Konvalinka

This article deals with time development of basic mechanical properties of steel fibers reinforced high strength concrete (FRHSC). The basic mechanical properties were studied at different age of the fiber reinforced high strength concrete, exactly at the age 12, 15, 18 and 21 hours and 1, 2, 3, 7, 14, 21 and 28 days. The compressive strength was determined by using cubic specimens (100 x 100 x 100 mm). The tensile strength in bending and fragment compressive strength after bending were determined by prismatic specimens (40 x 40 x 160 mm). Bulk density were determined too. The comparison of mechanical properties of fibers reinforced high strength concrete and high strength concrete is in conclusion of this article.


2011 ◽  
Vol 217-218 ◽  
pp. 113-118 ◽  
Author(s):  
Dong Sheng Shi ◽  
Yoshihiro Masuda ◽  
Young Ran Lee

In this experiment, blast furnace slag fine aggregate that was produced by 3 different steel factory was been used in high-strength concrete, and mechanical properties of high-strength concrete were studied. The concrete using the blast furnace slag fine aggregate is admitted the increase of compressive strength as well as the case of the river sand when the water cement ratio is reduced, and the compressive strength can attain 100N/mm2. The strength of concrete using blast furnace slag fine aggregate is lower than the strength of concrete using natural river sand as fine aggregate, and the strength of concrete using mixture fine aggregate is middle of strength used river sand and strength used blast furnace slag fine aggregate. The crushing value of blast furnace slag fine aggregate is bigger than the natural river sand, and it could influence the strength of high-strength concrete using blast furnace slag fine aggregate.


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