scholarly journals Mechanical Performance of High-Strength Sustainable Concrete under Fire Incorporating Locally Available Volcanic Ash in Central Harrat Rahat, Saudi Arabia

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 21
Author(s):  
Muhammad Nasir Amin ◽  
Kaffayatullah Khan
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elevated Temperature ◽  
Volcanic Ash ◽  
Elevated Temperatures ◽  
Mechanical Performance ◽  
High Strength ◽  
Pulse Velocity ◽  
Sustainable Concrete ◽  
Harrat Rahat

This study investigated the effect of elevated temperatures on the mechanical properties of high-strength sustainable concrete incorporating volcanic ash (VA). For comparison, control and reference concrete specimens with fly ash (FA) were also cast along with additional specimens of VA and FA containing electric arc furnace slag (EAFS). Before thermal exposure, initial tests were performed to evaluate the mechanical properties (compressive strength, tensile strength, and elastic modulus) of cylindrical concrete specimens with aging. Additionally, 91 day moist-cured concrete specimens, after measuring their initial weight and ultrasonic pulse velocity (UPV), were exposed up to 800 °C and cooled to air temperature. Subsequently, the weight loss, residual UPV, and mechanical properties of concrete were measured with respect to exposure temperature. For all concrete specimens, test results demonstrated a higher loss of weight, UPV, and other mechanical properties under exposure to higher elevated temperature. Moreover, all the results of concrete specimens incorporating VA were observed before and after exposure to elevated temperature as either comparable to or slightly better than those of control and reference concrete with FA. According to the experimental results, a correlation was developed between residual UPV and residual compressive strength (RCS), which can be used to assess the RCS of fire-damaged concrete (up to 800 °C) incorporating VA and EAFS.

scholarly journals Effect of polypropylene fibers on high strength mortar subjected to elevated temperature

2020 ◽  
Vol 156 ◽  
pp. 05010
Author(s):  
Muhammad Ridwan ◽  
Hu Liang Jun ◽  
Isamu Yoshitake
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elevated Temperature ◽  
Flexural Strength ◽  
Fiber Length ◽  
Heating Temperature ◽  
High Strength ◽  
Polypropylene Fibers ◽  
Slump Flow ◽  
Residual Mechanical Properties

This study focuses on the thermo-mechanical properties of mortar in the retrofitting cover of additional reinforcement for existing concrete structures. In addition, the residual mechanical properties of high strength mortar incorporating polypropylene fibers subjected to the effect of fiber length and the elevated temperature were investigated. Several experiments were conducted to determine the optimum mixture proportions of high strength mortar incorporating polypropylene fibers which had a slump-flow of 25–30 cm, compressive strength of 50 MPa or higher, and flexural strength of 4–8 MPa. Subsequently, an experiment was conducted by using high-strength mortar-blended polypropylene fibers with a length of 2 cm, and the ratio of fiber length to the diameter of cylinder mortar-specimens was 0.4. The experimental parameters were the weight volume of fibers (0 %, 0.5 %, 1 %, and 2%) and the heating temperature (100, 200 and 300 °C). The effect of the mixing parameters, including polypropylene length on compressive strength, slump-flow and the flexural strength of mortar were discussed. It is evident that fiber in the mortar cover influenced the initial and residual mechanical properties, such as elasticity, compressive strength, and Poisson’s ratio, of the mortar.

scholarly journals Experimental Evaluation of Untreated and Pretreated Crumb Rubber Used in Concrete

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 558
Author(s):  
Hamad Hassan Awan ◽  
Muhammad Faisal Javed ◽  
Adnan Yousaf ◽  
Fahid Aslam ◽  
Hisham Alabduljabbar ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Water Treatment ◽  
Mechanical Performance ◽  
Strength Loss ◽  
Ultrasonic Pulse Velocity ◽  
Crumb Rubber ◽  
Pulse Velocity ◽  
Unit Weight ◽  
Lime Treatment

The present research aims at evaluating the mechanical performance of untreated and treated crumb rubber concrete (CRC). The study was also conducted to reduce the loss in mechanical properties of CRC. In this study, sand was replaced with crumb rubber (CR) with 0%, 5%, 10%, 15%, and 20% by volume. CR was treated with NaOH, lime, and common detergent for 24 h. Furthermore, water treatment was also carried out. All these treatments were done to enhance the mechanical properties of concrete that are affected by adding CR. The properties that were evaluated are compressive strength, indirect tensile strength, unit weight, ultrasonic pulse velocity, and water absorption. Compressive strength was assessed after 7 and 28 days of curing. The mechanical properties were decreased by increasing the percentage of the CR. The properties were improved after the treatment of CR. Lime treatment was found to be the best treatment of all four treatments followed by NaOH treatment and water treatment. Detergent treatment was found to be the worse treatment of all four methods of treatment. Despite increasing the strength it contributed to strength loss.

Thermal performance of self-compacting concrete: destructive and nondestructive evaluation

2013 ◽  
Vol 40 (12) ◽  
pp. 1205-1214 ◽  
Author(s):  
Rami H. Haddad ◽  
Ruba A. Odeh ◽  
Hala A. Amawi ◽  
Ayman N. Ababneh
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Elevated Temperature ◽  
Elevated Temperatures ◽  
Mechanical Response ◽  
Compressive Strain ◽  
Peak Stress ◽  
Pulse Velocity ◽  
Self Compacting Concrete ◽  
Damage Indices

Recently, self-compacting concrete (SCC) has been increasingly used in high-rise buildings and industrial units, susceptible to accidental fires. The probable degradation of these structures necessitates understanding SCC behavior under elevated temperatures. For this, an extensive experimental investigation was undertaken to evaluate the effect of elevated temperature (300–600 °C) on the mechanical compressive properties of SCC; considering the effect of water-to-cement ratio (0.40–0.50), type of mineral aggregate and filler (limestone and basalt), and internal humidity. Standard cylinder (150 mm × 300 mm) and prism (100 mm × 100 mm × 300 mm) specimens were prepared from various SCC mixtures, cured for 28 d in limewater, and then stored at different environments for an additional 90 d to create varying internal humidity levels; ranging from 28 to 95%. Later, specimens were subjected to elevated temperatures in an electrical furnace, then cooled and tested for compressive mechanical response or non-destructively using resonance frequency, ultrasonic pulse velocity, and rebound hammer evaluation techniques. The results showed significant reduction in residual compressive strength, and elastic modulus, and an increase in compressive strain at peak stress and toughness as elevated temperature was increased. The SCC mixtures at upper water-to-cement ratios with basalt aggregate showed higher resistance to elevated temperatures than corresponding ones with limestone. Internal humidity in SCC had a detrimental impact on compressive strength and elastic modulus; especially at exposure temperatures below 400 °C. The statistical correlations between residuals for compressive strength or elastic modulus and nondestructive damage indices can be classified as very good. Furthermore, the nonlinear empirical models, developed to predict residuals for compressive strength and elastic modulus in terms of the study parameters, showed relatively high prediction potential, hence are recommended to be used in designing SCC mixtures for best resistance against possible fire attack.

Influence of an Elevated Temperature Environment on the Tensile Mechanical Properties of a 3D Printed Thermoplastic Polymer

2019 ◽  
Author(s):  
Jose E. Torres ◽  
Otito N. Onwuzurike ◽  
Amber J. W. McClung ◽  
Juan D. Ocampo
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Mechanical Testing ◽  
Elevated Temperatures ◽  
Mechanical Performance ◽  
Material Behavior ◽  
Experimental Program ◽  
Thermoplastic Polymer ◽  
3D Printed ◽  
Property Changes

Abstract The purpose of this study is to examine the effects of the environment on 3D printed Polylactic Acid (PLA), a biodegradable thermoplastic polymer. The experimental program was specifically designed to explore the influence of print temperature and aging temperature on the mechanical performance of the printed material. Printing at the elevated temperatures (30–40°C) resulted in slight mechanical property changes. In order to understand which of the changes could also be caused by simply storing the materials at the elevated temperature, samples were printed at 25°C and subsequently aged (at 30–45°C) before mechanical testing. All mechanical testing was performed in standard laboratory temperature on an MTS Criterion. All of the mechanical properties were not greatly altered by printing or aging at elevated temperatures, suggesting that printing and using in extreme weather environments could be reasonable. The yield stress is not affected by storage at elevated temperatures, but is increased (or enhanced) by printing at elevated temperatures. The maximum stress is increased (or enhanced) by both aging and printing at elevated temperatures, but is accompanied by a large reduction in strain capacity. Changes that are observed in mechanical properties will be incorporated in future material models to accurately capture material behavior.

scholarly journals Mechanical Properties of Fibre Reinforced Polymers under Elevated Temperatures: An Overview

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2600
Author(s):  
Milad Bazli ◽  
Milad Abolfazli
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperatures ◽  
Mechanical Performance ◽  
Weight Ratio ◽  
High Strength ◽  
Civil Infrastructures ◽  
Frp Composites ◽  
Frp Composite ◽  
Materials Used ◽  
Strength And Stiffness

Fibre-reinforced polymer (FRP) composite is one of the most applicable materials used in civil infrastructures, as it has been proven advantageous in terms of high strength and stiffness to weight ratio and anti-corrosion. The performance of FRP under elevated temperatures has gained significant attention among academia and industry. A comprehensive review on experimental and numerical studies investigating the mechanical performance of FRP composites subjected to elevated temperatures, ranging from ambient to fire condition, is presented in this paper. Over 100 research papers on the mechanical properties of FRP materials including tensile, compressive, flexural and shear strengths and moduli are reviewed. Although they report dispersed data, several interesting conclusions can be drawn from these studies. In general, exposure to elevated temperatures near and above the resin glass transition temperature, Tg, has detrimental effects on the mechanical characteristics of FRP materials. On the other hand, elevated temperatures below Tg can cause low levels of degradation. Discussions are made on degradation mechanisms of different FRP members. This review outlines recommendations for future works. The behaviour of FRP composites under elevated temperatures provides a comprehensive understanding based on the database presented. In addition, a foundation for determining predictive models for FRP materials exposed to elevated temperatures could be laid using the finding that this review presents.

Mechanical Properties of Concrete with Aggregate Type at Elevated Temperature

2011 ◽  
Vol 311-313 ◽  
pp. 1840-1846 ◽  
Author(s):  
Tae Gyu Lee ◽  
Gyu Yong Kim ◽  
Young Sun Kim ◽  
Gyu Yeon Park
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elevated Temperature ◽  
Elevated Temperatures ◽  
Research Effort ◽  
Thermal Strain ◽  
Normal Weight ◽  
Light Weight ◽  
Normal Weight Concrete ◽  
Light Weight Concrete

This research effort aims to evaluate the mechanical properties of concrete with two aggregate type, light weight and normal weight at elevated temperatures. To understand the mechanical properties at elevated temperature, normal and light weight concrete of 60 MPa grade was exposed to temperature range 20 to 700°C under 0%, 20%, 40% load conditions and compressive strength, elastic modulus, thermal strain and transient creep at target temperature were inspected. Experimental results show that light weight concrete has higher compressive strength, although the strength of normal weight concrete degenerated more sharply than the light weight concrete at elevated temperature. Moreover, the thermal strain (0% unstressed) and total strain (20%, 40% stressed) of normal weight concrete was higher than that of light weight concrete. Loading conditions significantly influenced the mechanical properties of normal weight concrete compared to that of light weight concrete at high temperature.

scholarly journals Mechanical Properties of Concrete with Steel and Polypropylene Fibres at Elevated Temperatures

Fibers ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 9 ◽  
Author(s):  
Josipa Bošnjak ◽  
Akanshu Sharma ◽  
Kevin Grauf
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Elevated Temperature ◽  
High Strength Concrete ◽  
Elevated Temperatures ◽  
High Strength ◽  
Fibre Reinforced Concrete ◽  
Explosive Spalling ◽  
Steel Fibres ◽  
Strength Concrete

Addition of steel fibres to concrete is known to have a significant positive influence on the mechanical properties of concrete. Micro polypropylene (PP) fibres are added to concrete to improve its performance under thermal loads such as in case of fire by preventing the phenomena of explosive spalling. An optimum mixture of steel and micro PP fibres added to concrete may be utilized to enhance both the mechanical and thermal behaviour of concrete. In this work, systematic investigations were carried out to study the influence of elevated temperature on the mechanical properties and physical properties of high strength concrete without and with fibres. Three different mixtures for high strength concrete were used, namely normal concrete without fibres, Steel fibre reinforced concrete and Hybrid fibre reinforced concrete having a blend of hooked end steel fibres and micro PP fibres. The specimens were tested in ambient conditions as well as after exposure to a pre-defined elevated temperature and cooling down to room temperature. For all investigated concrete mixtures the thermal degradation of following properties were investigated: compressive strength, tensile splitting strength, bending strength, fracture energy and static modulus of elasticity. This paper summarizes the findings of the tests performed.

Performance of spent garnet as a sand replacement in high-strength concrete exposed to high temperature

2019 ◽  
Vol 10 (4) ◽  
pp. 468-481 ◽  
Author(s):  
Mariyana Aida Ab Kadir ◽  
Mohammad Iqbal Khiyon ◽  
Abdul Rahman Mohd. Sam ◽  
Ahmad Beng Hong Kueh ◽  
Nor Hasanah Abdul Shukor Lim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Elevated Temperature ◽  
High Strength Concrete ◽  
Elevated Temperatures ◽  
High Strength ◽  
Concrete Cover ◽  
Content Type ◽  
Concrete Production ◽  
Natural Aggregates

Purpose The purpose of this paper is to examine the mechanical properties, material composition of spent garnet as a sand replacement in high-strength concrete at room and elevated temperatures. Bonding of the concrete containing spent garnet and reinforcing rebar is investigated. Moreover, the optimum thickness of concrete cover subjected to elevated temperatures is investigated. Design/methodology/approach First, the plain spent garnet was physically, chemically and thermally studied. Then, a series of concrete specimens with 0, 20, 40, 60, 80 and 100 per cent of spent garnet were prepared to determine the optimum percentage of spent garnet. Finally, the physical and mechanical behaviours of concrete specimens and effects of cover thickness on steel rebar when subjected to elevated temperature of 200°C, 400°C, 600°C and 800°C for 1 h were studied. It was observed that spent garnet was thermally stable compared to river sand. Findings Mechanical properties were found to be optimal for concrete with 40% spent garnet replacement. Physically, spent garnet concrete changed colour to brown at 400°C, and to whitish grey at 600°C. The residual compressive strength of spent garnet concrete was also found slightly higher than that for control specimens. At various high temperatures, the reduction in ultimate tensile stress for steel bar inside concrete cover of 30 mm was the lowest compared to that of 20 mm. Research limitations/implications Spalling effect it not considered in this study. Practical implications The optimum concrete cover is important issues in reinforced concrete design. This can be used as a guideline by structural designers when using a different type of concrete material in the construction. Social implications Utilization of the waste spent garnet reduces usage of natural aggregates in concrete production and enhances its performance at elevated temperatures. Natural aggregates are normally taken from sand and rock. The new innovation in concrete perhaps can produce light concrete, reduce the cost of concrete production and at the same time also mitigates environmental problems affect from waste material such as minimizing disposal area. Originality/value Utilization of spent garnet in ordinary Portland cement (OPC) concrete at high temperature is a new innovation. It shows that the concrete cover of the concrete element reduced as compared to the OPC concrete. Reduce in weight concrete however the strength of concrete is similar to conventional concrete. This study at elevated temperature has never been performed by any previous researcher.

CARLSON ALLOY C600 and C600 ESR

Alloy Digest ◽  
1994 ◽  
Vol 43 (11) ◽  
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Fracture Toughness ◽  
Cold Working ◽  
Elevated Temperatures ◽  
High Strength ◽  
Heat Treating ◽  
Solid Solution Alloy ◽  
Resistance To Oxidation ◽  
Good Workability

Abstract CARLSON ALLOYS C600 AND C600 ESR have excellent mechanical properties from sub-zero to elevated temperatures with excellent resistance to oxidation at high temperatures. It is a solid-solution alloy that can be hardened only by cold working. High strength at temperature is combined with good workability. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, and machining. Filing Code: Ni-470. Producer or source: G.O. Carlson Inc.

scholarly journals Microstructure and Mechanical Performance of Resistance Spot Welded Martensitic Advanced High Strength Steel

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1021
Author(s):  
Yunzhao Li ◽  
Huaping Tang ◽  
Ruilin Lai
Keyword(s):  
Mechanical Properties ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Strong Dependence ◽  
High Strength ◽  
Weld Nugget ◽  
Resistance Spot ◽  
Pull Out ◽  
Cross Tension ◽  
Spot Welded

Resistance spot welded 1.2 mm (t)-thick 1400 MPa martensitic steel (MS1400) samples are fabricated and their microstructure, mechanical properties are investigated thoroughly. The mechanical performance and failure modes exhibit a strong dependence on weld-nugget size. The pull-out failure mode for MS1400 steel resistance spot welds does not follow the conventional weld-nugget size recommendation criteria of 4t0.5. Significant softening was observed due to dual phase microstructure of ferrite and martensite in the inter-critical heat affected zone (HAZ) and tempered martensite (TM) structure in sub-critical HAZ. However, the upper-critical HAZ exhibits obvious higher hardness than the nugget zone (NZ). In addition, the mechanical properties show that the cross-tension strength (CTS) is about one quarter of the tension-shear strength (TSS) of MS1400 weld joints, whilst the absorbed energy of cross-tension and tension-shear are almost identical.

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