Comparison of compressive and splitting tensile strength of high-strength concrete with and without polypropylene fibers heated to high temperatures

2009 ◽  
Vol 44 (8) ◽  
pp. 1015-1022 ◽  
Author(s):  
Ali Behnood ◽  
Masoud Ghandehari
2020 ◽  
Vol 402 ◽  
pp. 50-55 ◽  
Author(s):  
Muttaqin Hasan ◽  
Aulia Desri Datok Riski ◽  
Taufiq Saidi ◽  
Husaini ◽  
Putroe Nadhilah Rahman

This paper presents the flexural and splitting tensile strength of high strength concrete (HSC) with diatomite micro particles (DMP) as a mineral additive. In order to have micro particles, the diatomite from Aceh Besar District was ground and sieved with sieve size of 250 mm. The particles were then calcined at the temperature of 600 °C for 5 hours. Four mixtures were designed with different DMP to binder ratio (DMP/b). The ratio was 0%, 5%, 10% and 15%, and the water to binder ratio was 0.3. Four beam specimens with a size of 10 cm × 10 cm × 40 cm and four cylinder-specimens with 10 cm diameter and 20 cm high were prepared for each mixture. Flexural and splitting tensile tests were conducted based on ASTM C78 and ASTM C496/496M. The maximum flexural strength was reached at DMP/b of 5% while the maximum splitting tensile strength was reached at DMP/b of 0%.


2010 ◽  
Vol 34-35 ◽  
pp. 1441-1444 ◽  
Author(s):  
Ju Zhang ◽  
Chang Wang Yan ◽  
Jin Qing Jia

This paper investigates the compressive strength and splitting tensile strength of ultra high strength concrete containing steel fiber. The steel fibers were added at the volume fractions of 0%, 0.5%, 0.75%, 1.0% and 1.5%. The compressive strength of the steel fiber reinforced ultra high strength concrete (SFRC) reached a maximum at 0.75% volume fraction, being a 15.5% improvement over the UHSC. The splitting tensile strength of the SFRC improved with increasing the volume fraction, achieving 91.9% improvements at 1.5% volume fraction. Strength models were established to predict the compressive and splitting tensile strengths of the SFRC. The models give predictions matching the measurements. Conclusions can be drawn that the marked brittleness with low tensile strength and strain capacities of ultra high strength concrete (UHSC) can be overcome by the addition of steel fibers.


2020 ◽  
Vol 26 (1) ◽  
pp. 118-127
Author(s):  
Teuku Budi Aulia ◽  
Muttaqin Muttaqin ◽  
Mochammad Afifuddin ◽  
Zahra Amalia

High-strength concrete is vulnerable to high temperatures due to its high density. The use of polypropylene fibers could prevent structure explosion by forming canals due to melted fibers during fire, thus release its thermal stress. This study aims to determine the effect of polypropylene fibers on compressive strength of high-strength concrete after combustion at 400ºC for five hours. High-strength concrete was made by w/c-ratio 0.3 with cement amount 550 kg/m3 and added with silica fume 8% and superplasticizer 4% by cement weight. The variations of polypropylene fibers were 0%, 0.2% and 0.4% of concrete volume. The compression test was carried out on standard cylinders Ø15/30 cm of combustion and without combustion specimens at 7 and 28 days. The results showed that compressive strength of high-strength concretes without using polypropylene fibers decreased in post-combustion compared with specimens without combustion, i.e., 0.81% at 7 days and 23.42% at 28 days. Conversely, the use of polypropylene fibers can increase post-combustion compressive strength with a maximum value resulted in adding 0.2% which are 25.52% and 10.44% at 7 and 28 days respectively. It can be concluded that the use of polypropylene fibers is effective to prevent reduction of high-strength concrete compressive strength that are burned at high temperatures.


2021 ◽  
Vol 45 (4) ◽  
pp. 351-359
Author(s):  
Noor Alhuda Sami Aljabbri ◽  
Mohammed Noori Hussein ◽  
Ali Abdulmohsin Khamees

Fire or high temperature is a serious issue to ultra-high-strength concrete (UHSC). Strength reduction of UHPCs may amount to as high as 80 percent after exposure to 800℃. A sum of four UHSC mixes was synthesized and evaluated in this study after getting exposed to extreme temperatures that reach 1000°C. Steel and polypropylene (PP) fibers were used in this experiment. A total of four mixes were made of UHSC without fibres as a control mix (UHSC-0), UHSC with 2% steel fibres (UHSC-S), UHSC with 2% PP fibres (UHSC-P) and UHSC with 1% steel fibres + 1% PP fibres (UHSC-SP). Workability, direct tensile strength, compressive strength, and splitting tensile strength were examined. Particularly, emphasis was devoted to explosive spalling since UHPCs are typically of compact structure and hence more prone to explosive spalling than other concretes. It was determined that the mixture UHSC-SP had high fire resistance. Following exposure to 1000℃, this mixture preserved a residual compressive strength of 36 MPa, splitting tensile strength of 1.62 MPa and direct tensile strength of 0.8 MPa. On the other hand, UHSC-P also had good fire resistance while UHSC-0 and UHSC-S experienced explosive spalling after heating above 200ᴼC. The incorporation of steel fibers in UHSC-S and UHSC-SP mixtures reveals higher tensile and compressive strength findings at different elevated temperatures as compared to UHSC-0 and UHSC-P. In addition, the result of direct tensile strength appears to be lower than splitting tensile strength at different raised temperatures.


Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5313 ◽  
Author(s):  
Nao Lv ◽  
Hai-bo Wang ◽  
Qi Zong ◽  
Meng-xiang Wang ◽  
Bing Cheng

In view of the devastating outcomes of fires and explosions, it is imperative to research the dynamic responses of concrete structures at high temperatures. For this purpose, the effects of the strain rate and high temperatures on the dynamic tension behavior and energy characteristics of high-strength concrete were investigated in this paper. Dynamic tests were conducted on high-strength concrete after exposure to the temperatures of 200, 400, and 600 °C by utilizing a 74 mm diameter split Hopkinson pressure bar (SHPB) apparatus. We found that the quasi-static and dynamic tensile strength of high-strength concrete gradually decreased and that the damage degree rose sharply with the rise of temperature. The dynamic tensile strength and specific energy absorption of high-strength concrete had a significant strain rate effect. The crack propagation law gradually changed from directly passing through the coarse aggregate to extending along the bonding surface between the coarse aggregate and the mortar matrix with the elevation of temperature. When designing the material ratio, materials with high-temperature resistance and high tensile strength should be added to strengthen the bond between the mortar and the aggregate and to change the failure mode of the structure to resist the softening effect of temperature.


2010 ◽  
Vol 150-151 ◽  
pp. 996-999
Author(s):  
Chang Wang Yan ◽  
Jin Qing Jia ◽  
Ju Zhang ◽  
Rui Jiang

The marked brittleness with low tensile strength and strain capacities of ultra high strength concrete (UHSC) with compressive strength of 100 MPa can be overcome by the addition of polyvinyl alcohol (PVA) fibers. The compressive strength and splitting tensile strength of ultra high strength concrete containing PVA fibers are investigated this paper. The PVA fibers were added at the volume fractions of 0%, 0.17%, 0.25%, 0.34% and 0.5%. The compressive strength of the PVA fiber reinforced ultra high strength concrete (PFRC) reached a maximum at 0.5% volume fraction, being an 8.2% improvement over the UHSC. The splitting tensile strength of the PFRC improved with increasing the volume fraction, achieving 46.7% improvements at 0.5% volume fraction. The splitting strength models were established to predict the compressive and splitting tensile strengths of the PFRC. The models give predictions matching the measurements.


2014 ◽  
Vol 629-630 ◽  
pp. 112-118
Author(s):  
Juan Yang ◽  
Gai Fei Peng

An experimental investigation on the variation of compressive strength, splitting tensile strength and fracture energy, with the ratios of water to binder (W/B) of ultra-high strength concretes, including the reactive power concrete (RPC) and ultra-high strength concrete with coarse aggregate (UHSC), has been carried out. The W/B varied between 0.14 and 0.22 at a constant increment of 0.02. It was observed that, compressive strength of RPC almost remained the unchanged, when the W/B was between 0.14 and 0.18. However, it decreased dramatically when the ratios were 0.20 and 0.22. For UHSC, the compressive strength was the highest value at the ratio of 0.18. The results of the two concretes could not comply with the Abrams' generalized W/B ratio law. Moreover, splitting tensile strength of RPC and UHSC decreased continually as the ratio increased from 0.14 to 0.22. Fracture energy of RPC was more or less the same when the ratios were between 0.16 and 0.20, and the maximum value was at 0.14. Fracture energy was observed to be almost no variation for UHSC at all ratios


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.


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