Post-thermal properties of Portland cement concrete made with copper slag as fine aggregates

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
N. Suresh ◽  
Manjunatha M.
Keyword(s):  
Compressive Strength ◽  
Elevated Temperature ◽  
Copper Slag ◽  
Strength Properties ◽  
Thermal Strength ◽  
Physical Test ◽  
Content Type ◽  
Slag Content ◽  
Sem Studies

Purpose The purpose of this paper is to investigate the effect of elevated temperature on mechanical and physical properties of concrete specimens obtained by substituting the river sand with copper slag (CS) at proportions of 25%, 50%, 75% and 100%. The specimens were heated in an electric furnace up to 100, 200, 300, 400, 500 and 600 C and kept at these temperatures for 2 h duration. After the specimens were cooled in the furnace, mass loss, ultrasonic pulse velocity (UPV), compressive strength, split tensile strength (STS), flexural strength (FS) and modulus of elasticity (MOE) values were determined. No spalling occurred in the specimens after subjected to elevated temperature. The surface cracks were observed only in specimens exposed to 600 C. The maximum reduction in compressive strength and STS at 600C is 50.3% and 36.39% for referral mix (NC), 18% and 16% for specimens with 100% CS (MCS4). The reduction in MOE of specimens is observed to be high as copper slag content increases with increasing temperature. Scanning electron microscopy (SEM) studies are carried out to examine the changes in micro-structures of specimens after exposed to elevated temperatures. Design/methodology/approach After casting of concrete specimens, it is cured for 28 days. After attainment of 28 days age, the concrete specimens is taken out from the curing tank and allowed to dry for 2 days to remove any moisture content in the specimens to prevent explosive spalling during the time of heating. The prepared concrete specimen is subjected to temperatures of 100°C, 200°C, 300°C, 400°C, 500°C and 600°C up to 2 h duration. The physical test, mechanical test and SEM studies are carried out after cooling of specimens to room temperature (RT). The quality of concrete specimens is measured by conducting UPV test after cooling to RT. Findings The post-thermal strength properties of concrete specimens with copper slag contents are higher than referral mix concrete. The reduction of MOE of concrete specimens is more with incremental in copper slag content with increase in temperatures. Furthermore, the quality of concrete specimens is ranging from “good to medium” up to 500C temperatures based on UPV test. Originality/value In this research work, the natural sand is fully replaced with copper slag materials in the concrete mixes. The post-thermal strength properties like residual compressive strength, residual STS, residual FS and residual MOE is higher than referral mix after subjected to elevated temperature conditions. Higher density and toughness properties of copper slag materials will contribute to concrete strength. The effect of elevated temperature is more on MOE of concrete specimens having higher copper slag contents when comparing to specimens compressive strength.

Effect of using magnetic water on the mechanical properties of concrete exposed to elevated temperature

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wasim Barham ◽  
Ammar AL-Maabreh ◽  
Omar Latayfeh
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Elevated Temperature ◽  
Flexural Strength ◽  
Tap Water ◽  
Splitting Tensile Strength ◽  
Content Type ◽  
Normal Water ◽  
Magnetic Water

PurposeThe influence of using magnetic water instead of tap water in the mechanical properties of the concrete exposed to elevated temperatures was investigated. Two concrete mixes were used and cast with the same ingredients. Tap water was used in the first mix and magnetic water was used in the second mix. A total of 48 specimens were cast and divided as follows: 16 cylinders for the concrete compressive strength test (8 samples for each mix), 16 cylinders for the splitting tensile strength (8 specimens for each mix) and 16 beams to test the influences of magnetized water on the flexural strength of concrete (8 specimens for each mixture). Specimens were exposed to temperatures of (25 °C, 200 °C, 400 °C and 600 °C). The experimental results showed that magnetic water highly affected the mechanical properties of concrete. Specimens cast and curried out with magnetic water show higher compressive strength, splitting tensile strength and flexural strength compared to normal water specimens at all temperatures. The relative strength range between the two types of water used was 110–123% for compressive strength and 110–133% for splitting strength. For the center point loading test, the relative flexural strength range was 118–140%. The use of magnetic water in mixing concrete contribute to a more complete hydration process.Design/methodology/approachExperimental study was carried out on two concrete mixes to investigate the effect of magnetic water. Mix#1 used normal water as the mixing water, and Mix#2 used magnetic water instead of normal water. After 28 days, all the samples were taken out of the tank and left to dry for seven days, then they were divided into different groups. Each group was exposed to a different temperature where it was placed in a large oven for two hours. Three different tests were carried out on the samples, these tests were concrete compressive strength, flexural strength and splitting tensile strength.FindingsExposure of concrete to high temperatures had a significant influence on concrete mechanical properties. Specimens prepared using magnetic water showed higher compressive strength at all temperature levels. The use of magnetic water in casting and curing concrete can increase the compressive strength by 23%. Specimens prepared using magnetic water show higher splitting tensile strength at all temperatures up to 33%. The use of magnetic water in casting and curing can strengthen and increase concrete resistance to high temperatures, a significant enhancement in flexural strength at all temperatures was found with a value up to 40%.Originality/valuePrevious research proved the advantages of using magnetic water for improving the mechanical properties of concrete under normal conditions. The potential of using magnetic water in the concrete industry in the future requires conducting extensive research to study the behavior of magnetized concrete under severe conditions to which concrete structures may be subjected to. These days, there are attempts to obtain stronger concrete with high resistance to harsh environmental conditions without adding new costly ingredients to its main mixture. No research has been carried out to investigate the effect of magnetic water on the mechanical properties of concrete exposed to elevated temperature. The main objective of this study is to evaluate the effect of using magnetic water on the mechanical properties of hardened concrete subjected to elevated temperature.

scholarly journals EFFICACY OF BASALT AND GRANITE AS COARSE AGGREGATE IN CONCRETE MIXTURE

2020 ◽  
Vol 7 (9) ◽  
pp. 1-9
Author(s):  
S.E Ubi ◽  
P.O Nkra ◽  
R.B Agbor ◽  
D.E Ewa ◽  
M. Nuchal
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Specific Gravity ◽  
Coarse Aggregate ◽  
Strength Properties ◽  
Test Results ◽  
Physical Test ◽  
Coarse Aggregates ◽  
Structural Tests ◽  
Comparative Results

This present research was on the comparison of the efficacious use of basalt and granite as coarse aggregates in concrete work. In order to obtain the basis for comparison, physical and structural tests were conducted on the different materials of the concrete and the concrete samples respectively. Physical test results revealed that basalt have a specific gravity of 2.8 and 2.5, while granite have a specific gravity of 2.9 and 2.6. In density, basalt have a density of 1554.55kg/m3 while granite had a density of 1463.64kg/m3. Aggregate impact test conducted on both aggregates revealed a percentage of 11.05% for basalt and 12.63% for granite. The following structural tests were carried out: compressive strength tests, flexural and tensile strength test and the comparative results are as follows. Compressive strength for basalt 36.39N/mm2 while 37.16N/mm2 for granite. 24.81N/mm2 tensile strength for basalt while 12.57N/mm2 for granite, 31.83N/mm2 flexural strength for basalt while 27.97N/mm2 for granite. From the above results, it can be deduced that basalt has higher strength properties than granite. Therefore, more suitable for coarse aggregate in achieving higher strength with some quantity of other composition of the concrete mix when compared to granite.

An IoT device for striking of vertical concrete formwork

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shemin T. John ◽  
Athul Mohan ◽  
Merin Susan Philip ◽  
Pradip Sarkar ◽  
Robin Davis
Keyword(s):  
Compressive Strength ◽  
Real Time ◽  
Cost Effective ◽  
Concrete Columns ◽  
Content Type ◽  
Maturity Method ◽  
Early Age Concrete ◽  
Construction Condition ◽  
Practical Implications

PurposeTimely removal of formwork is one of the crucial aspects of construction management that directly influences the safety and quality of the structure as well as the economy of the project. Code recommendations in this regard are not widely practiced because of the difficulties in their implementations. Also, such code recommendations are not robust for all the possible construction conditions. The present paper proposes an IoT-enabled system that notifies the minimum striking time of vertical formwork based on a specified target compressive strength.Design/methodology/approachAn IoT device is proposed for the timely removal of vertical formwork by monitoring of early age concrete compressive strength in real-time. The maturity method is utilized for this purpose. The implementation of the proposed system is demonstrated on three concrete columns. The proposed system is found to be suitable for any construction condition.FindingsThe proposed system is a novel, cost-effective, IoT-enabled real-time monitoring system which includes features like cloud connectivity and remote monitoring. This system can be easily implemented at the site without any human intervention.Practical implicationsThe study explores the development of an IoT device for the timely removal of vertical formwork which will ensure quality, safety and productivity in concrete construction.Originality/valueThis paper is the first attempt to determine the minimum striking time of vertical formwork using IoT-based technology.

STUDY ON THE INFLUENCE OF CURING TEMPERATURE ON MECHANICAL PROPERTIES OF MODIFIED FLY ASH MORTAR

2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Hirotaka Matsuo ◽  
Koji Takasu ◽  
Hidehiro Koyamada ◽  
Hiroki Suyama
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Strength Properties ◽  
Curing Temperature ◽  
Static Elasticity ◽  
Flotation Technique ◽  
Accumulated Temperature ◽  
Modified Fly Ash

Using fly ash as an admixture for concrete can contribute to environmental load reduction and concrete quality improvement. However, as the quality of fly ash fluctuates depending on the ash source, quality stabilization is required. It was proved that concrete with fly ash of Japanese Industrial Standardized class II has different strength properties depending on curing temperature, but it is not obvious whether concrete with modified fly ash by flotation method has similar properties. In this study, the influence was examined on the mechanical properties when changing the curing temperature of mortar using fly ash modified by the flotation technique. The sealing curing was set to 5°C, 20°C, 40°C and 60°C. Also, after 7 days, 5°C, 40°C and 60°C, is changed to 20°C and compression strength and static elasticity coefficient were measured. The value of compressive strength and static elastic modulus showed that mortar using modified fly ash had the same characteristics as mortar with ordinary fly ash. Because it was represented by one strength compressive estimation curve regardless of the curing temperature, it became clear that compressive strength can be evaluated by roughly using accumulated temperature as an indicator.

scholarly journals KAJIAN PENAMBAHAN PAPER SULDGE YANG BERVARIASI TERHADAP SIFAT FISIK DAN MEKANIK CEILING BRICK

BANGUNAN ◽  
2020 ◽  
Vol 25 (1) ◽  
pp. 41
Author(s):  
M. Abdul Aziz Kurniawan ◽  
Eko Suwarno ◽  
Boedya Djatmika
Keyword(s):  
Compressive Strength ◽  
Research Method ◽  
Strength Test ◽  
Paper Sludge ◽  
Physical Test ◽  
Water Seepage ◽  
Significant Difference ◽  
Compressive Strength Test ◽  
Sludge Waste

Abstrak:Ceiling brick buangan paper sludge salah satu alternatif membuat pelat lantai, secara ekonomis lebih murah dan memiliki kuat tekan setara dengan beton konvensional K300. Penelitian ini menggunakan metode eksperimen. Terdapat dua jenis benda uji yang digunakan yaitu berbentuk kubus dengan ukuran 5 cm x 5 cm x 5 cm untuk mengetahui kualitas bahan ceiling brick dan benda uji berbentuk produk ceiling brick untuk mengetahui kualitas produk ceiling brick. Variasi paper sludge yang digunakan adalah 2, 4, 6, dan 8 persen. Satu benda uji dilakukan dua pengujian yaitu uji fisik (rembesan air) dan mekanik (kuat tekan). Metode penelitian menggunakan analisa statistik One Way dan dilanjutkan analisis Tukey. Hasil dari penelitian ini adalah (1) Kuat tekan produk ceiling brick dengan campuran paper sludge berurut-urut 0, 2, 4, 6, dan 8 persen sebesar 8.43 MPa, 9.39 MPa, 11.28 MPa, 10.31 MPa, dan 8.30 MPa. Nilai rata-rata rembesan air produk ceiling brick dengan variasi berurut-urut 0%,2%, 4%, 6%, dan 8%, yaitu sebesar 0.35 ml/menit, 0.37 ml/menit, 0.35 ml/menit, 0.42 ml/menit, dan 0.36 ml/ menit. (2) Kuat tekan mortar kubus ceiling brick dengan campuran paper sludge berurut-urut 0, 2, 4, 6, dan 8 persen sebesar 105.66 MPa, 112.67 MPa, 104.20 MPa, 98.55 MPa, dan 105.24 MPa. Rembesan air mortar kubus ceiling brick dengan variasi berurut-urut 0, 2, 4, 6, dan 8 persen, yaitu sebesar 0,59 ml/menit, 0,54 ml/menit, 0,46 ml/menit, 0,27 ml/menit, dan 0,28 ml/menit. (3) Uji kuat tekan dan rembesan air terhadap produk ceiling brick yang telah dicampur paper sludge mengalami perbedaan tetapi tidak signifikan. (4) Uji kuat tekan terhadap mortar kubus ceiling brick yang dicampur paper sludge mengalami perbedaan tetapi tidak signifikan. Sedangkan uji rembesan air tehadap mortar kubus ceiling brick yang dicampur paper sludge mengalami perbedaan yang signifikan. (5) Campuran paper sludge 4 persen pada produk ceiling brick dan campuran paper sludge 2 persen pada mortar kubus ceiling brick menghasilkan kuat tekan optimum.Kata-kata kunci: paper sludge, limbah kertas, ceiling brick, sifat fisik & mekanikAbstract: Paper sludge ceiling bricks are an alternative to making floor plates, are economically cheaper and have compressive strength equivalent to conventional K300 concrete. This research is using experimental method. There are two types of specimens used which are cube shaped with a size of 5 cm x 5 cm x 5 cm to determine the quality of ceiling brick material and specimens in the form of ceiling brick products to determine the quality of ceiling brick products. Paper sludge variations used are 0, 2, 4, 6, dan 8 percent. One test object was carried out two tests, namely physical test (water seepage) and mechanical (compressive strength). The research method uses One Way statistical analysis and Tukey analysis continues. The results of this study are (1) Compressive strength of brick brick products with a mixture of paper sludge in sequence of 0, 2, 4, 6, dan 8 percent at 8.43 MPa, 9.39 MPa, 11.28 MPa, 10.31 MPa and 8.30 MPa. The average seepage value of ceiling brick products with sequential variations of 0, 2, 4, 6, dan 8 percent which is 0.35 ml / minute, 0.37 ml / minute, 0.35 ml / minute, 0.42 ml / minute minutes, and 0.36 ml / minute. (2) Compressive strength of ceiling brick cube mortar with a mixture of paper sludge in a sequence of 0, 2, 4, 6, dan 8 percent by 105.66 MPa, 112.67 MPa, 104.20 MPa, 98.55 MPa and 105.24 MPa. Mortar cube ceiling water seepage with sequential variations of 0, 2, 4, 6, dan 8 percent in the amount of 0.59 ml / minute, 0.54 ml / minute, 0.46 ml / minute, 0.27 ml / minute, and 0.28 ml / minute. (3) The compressive strength and water seepage tests on ceiling brick products that have been mixed with paper sludge experience differences but are not significant. (4) Compressive strength test of ceiling brick cube mortar mixed with paper sludge is different but not significant. While the water seepage test of ceiling brick cube mortar mixed with paper sludge experienced a significant difference. (5) 4 percent paper sludge mixture in ceiling brick products and 2 percent paper sludge mixture in ceiling brick cube mortars produce optimum compressive strength.Keywords: paper sludge, waste paper, ceiling brick, physical & mechanical properties

Flexural behaviour of reinforced self compacting concrete beams subjected to elevated temperature before and after retrofitting

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sachin B.P. ◽  
N. Suresh
Keyword(s):  
Compressive Strength ◽  
Elevated Temperature ◽  
Carrying Capacity ◽  
Modulus Of Elasticity ◽  
Concrete Beams ◽  
Load Carrying Capacity ◽  
Self Compacting Concrete ◽  
Content Type ◽  
Load Carrying ◽  
Before And After

Purpose The purpose of the paper is to study the effect of elevated temperature on load carrying capacity of reinforced self compacting concrete beams and the performance of deteriorated beams after retrofitting by GFRP sheets. The reinforced beams which were exposed to sustained elevated temperature and tested for flexural load-carrying capacity. Further deteriorated beams (exposed from 500°C to 800°C) were re-strengthened by adopting retrofitting with GFRP sheets. Design/methodology/approach The investigation includes the concrete specimens, i.e. cubes of 150 mm, cylinders of size 150 mm dia with 300 mm height and beams of 150 × 150 × 1,100 mm, reinforced with minimum tension reinforcement according to IS 456–2000. The specimens were subjected to elevated temperature from 300°C to 800°C with an interval of 100°C for 2 h. The residual compressive strength, modulus of elasticity, load at first crack of beams and load-carrying capacity of beams for 5-mm deflection were measured before and after retrofitting. Findings The result shows that there is a gain in residual compressive strength at 300°C and beyond which it decreases. The modulus of elasticity, load at first crack and load-carrying capacity of beams reduces continuously with an increase in temperature. The decrease in load-carrying capacity of beams is observed from 27.55% and up to 38.77% between the temperature range of 500°C–800°C and after the retrofitting of distressed beams, the load carrying capacity increases up to 24.48%. Originality/value Better performance was observed with retrofitting by GFRP sheets when the specimens were distressed due to elevated temperatures.

Numerical and experimental studies on sustainable alkali activated concretes at elevated temperatures

2019 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Subhash Yaragal ◽  
Chethan Kumar B. ◽  
Manoj Uddavolu Abhinav
Keyword(s):  
Compressive Strength ◽  
Elevated Temperature ◽  
Fly Ash ◽  
Elevated Temperatures ◽  
Experimental Studies ◽  
Optimization Techniques ◽  
Gray Relational Analysis ◽  
Complete Replacement ◽  
Content Type ◽  
Alkali Activated

Purpose To reduce environmental impact caused by excessive use of ordinary Portland cement (OPC) and to mitigate scarcity of base materials such as natural coarse aggregate (NCA), industrial by-products can be carefully used as alternatives to OPC and NCA, in production of concrete. This paper aims to describe the performance of using ground granulated blast furnace slag (GGBS), fly ash (FA) as a complete replacement to OPC and ferrochrome slag (FCS) as replacement to NCA in production of novel FCS based alkali activated slag/fly ash concretes (AASFC) and evaluate their performance at elevated temperatures. Design/methodology/approach Two control factors with three levels each i.e. FA (0, 25 and 50 per cent by weight) and FCS (0, 50 and 100 per cent by volume) as a GGBS and NCA replacement, respectively, were adopted in AASFC mixtures. Further, AASFC mixture specimens were subjected to different levels of elevated temperature, i.e. 200°C, 400°C, 600°C and 800°C. Compressive strength and residual compressive strength were considered as responses. Three different optimization techniques i.e. gray relational analysis, technique for order preference by similarity to ideal solution and Desirability function approach were used to optimize AASFC mixtures subjected to elevated temperatures. Findings As FA replacement increases in FCS based AASFC mixtures, workability increases and compressive strength decreases. The introduction of FCS as replacement to NCA in AASFC mixture did not show any significant change in compressive strength under ambient condition. AASFC produced with 75 per cent GGBS, 25 per cent FA and 100 per cent FCS was found to have excellent elevated temperature enduring properties among all other AASFC mixtures studied. Originality/value Although several studies are available on using GGBS, FA and FCS in production of OPC-based concretes, present study reports the performance of novel FCS based AASFC mixtures subjected to elevated temperatures. Further, GGBS, FA and FCS used in the present investigation significantly reduces CO2 emission and environmental degradation associated with OPC production and NCA extraction, respectively.

scholarly journals Flexural behaviour of steel fibre reinforced concrete beams made with copper slag as partial fine aggregate replacement

2020 ◽  
Vol 184 ◽  
pp. 01077
Author(s):  
DAS Mohd Areef ◽  
P Srinivasa Rao ◽  
V Srinivasa Reddy ◽  
D Mohd Azeem Zubair
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Free Water ◽  
Copper Slag ◽  
Reinforced Concrete Beams ◽  
Experimental Investigations ◽  
Fine Aggregate ◽  
River Sand ◽  
Slag Content

Lately, development of concrete using industrial byproducts has garnered major significance in the construction industry in order to overcome problems associated with depleted natural resources. As, river sand is costly and also large scale exhaustion of these sources generates environmental harms, a substitute or replacement product for concrete industry is very indispensable. In such a situation, the copper slag can be proposed as an alternative to the river sand, which is an industrial by-product obtained from the manufacturing of copper. The present investigation assesses the incorporation of copper slag in concrete (CSC). In this paper, experimental investigations are carried to understand the flexural characteristics such as such as first crack, ultimate load carrying capacity, maximum crack width and deflection at service load and at centre of steel fibred copper slag mixed under-reinforced concrete beams. Results showed that the compressive strength of concrete decreases as copper slag content increases beyond 40%. The reduction in compressive strength beyond 40% replacement of river sand due to the increase in free water content in concrete mixes due to the low absorption properties of copper slag which can cause excessive bleeding at higher copper slag content. The load-deflection behaviour of under-reinforced, normal and copper slag concrete beams is witnessed to be alike apart from the increased values of ultimate failure loads and ultimate deflections at failure in steel fibred copper slag concrete beams.

scholarly journals Assessment of the Mechanical Properties of Some Selected Sandcrete Hollow Blocks in Kogi State

2017 ◽  
Vol 2 (11) ◽  
pp. 43
Author(s):  
Ajibola Ibrahim Quadri ◽  
Lawrence Irobekhian Ijesoh
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Water Absorption ◽  
Strength Properties ◽  
Poor Quality ◽  
Regulatory Body ◽  
Sieve Analysis ◽  
Minimum Requirement ◽  
Analysis Of Results

The current wave of the collapse of building structure all over Nigeria necessitates the need to carry out research on the mechanical properties of sandcrete hollow blocks. This study looks into the quality of blocks produced by block industries in Kogi state, Nigeria to ascertain its water absorption ratio, compressive strength and sieve analysis. In order to clarify these problems, the study is directed towards testing the strength properties of commercially produced sandcrete blocks; to verify whether the sandcrete block can be improved to achieve good quality in the building industries.  A Total of five block industries were visited and twenty samples were picked at random from each of the selected block industry and also, soil samples obtained for soil tests in the laboratory. The analysis of results obtained was compared with the Nigerian Industrial Standard (NIS). The average water absorption rate of the sandcrete blocks for block industry D was found to be 12.5% higher than the 12% maximum requirement of the [9]. The average compressive strength values of the sandcrete blocks range between 0.64N/mm2 and 0.87N/mm2 which when compared with standard, was found to be below the minimum requirement of the [9]. Inadequate mix ratio was observed to be one of the factors of poor quality sandcrete block production in this area. The study recommends compliance monitoring by the various regulatory body to ensure good quality of sandcrete block production.

Performance of hybrid fibres on mechanical properties of self-compacting concrete at elevated temperature

2019 ◽  
Vol 10 (3) ◽  
pp. 262-274
Author(s):  
Sachin B.P. ◽  
N. Suresh
Keyword(s):  
Compressive Strength ◽  
Elevated Temperature ◽  
Carrying Capacity ◽  
Elevated Temperatures ◽  
Load Carrying Capacity ◽  
Self Compacting Concrete ◽  
Polypropylene Fibres ◽  
Content Type ◽  
Reinforced Beams ◽  
Load Carrying

Purpose The present experimental investigation attempts to study the behaviour of hybrid fibre-reinforced self-compacting concrete (HFSCC) subjected to elevated temperature. The purpose of this study is to find out the performance of hybrid fibres of 0.5 per cent by volume of concrete (out of which 75 per cent are steel fibres and 25 per cent, polypropylene fibres). Reinforced beams were casted and tested for the flexural load-carrying capacity, and comparisons were made with the load-carrying capacity of reinforced beams without the inclusion of fibres. Design/methodology/approach The study includes 60 concrete cubes of 150 mm and 60 beams of 150 × 150 × 1,100 mm reinforced with minimum tension reinforcement according to IS 456-2000. The specimens were subjected to elevated temperature from 100°C to 500°C with an interval of 100°C for 2 h. The residual compressive strength and the load-carrying capacity of beams for 5-mm deflection were measured. Parameters such as load at first crack, width and length of cracks developed on the beam during the application of load were also studied. Findings The result shows that for self-compacting concrete without fibres (SCCWOF), there is a gain in compressive strength between 200°C and 300°C, beyond which the strength decreases. For HFSCC, the gain in strength is between 300°C and 400°C, and thereafter the strength gets reduced. The load-carrying capacity of beams reduces with an increase in temperature. An increase in load-carrying capacity (up to 40.7 per cent) for HFSCC beams is observed when compared to SCCWOF beams at 500°C. Originality/value Better performance was observed with the usage of fibres when the specimens were subjected to elevated temperatures.

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