Residual Compressive Strength of Lightweight Foamed Concrete after Exposure to High Temperatures

2015 ◽  
Vol 747 ◽  
pp. 213-216 ◽  
Author(s):  
Md Azree Othuman Mydin ◽  
Mohd Yazid Mohd Yunos ◽  
Mohd Nasrun Mohd Nawi ◽  
Adi Irfan Che Ani
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Temperatures ◽  
Normal Weight ◽  
Compression Tests ◽  
Load Bearing ◽  
Residual Compressive Strength ◽  
Normal Weight Concrete ◽  
Foamed Concrete ◽  
Resistance Performance

Even though lightweight foamed concrete has low mechanical properties compared to normal weight concrete, there is a potential of using this material as partition or load-bearing wall in low-rise residential construction. Before it can be considered for use as a load-bearing element in the building industry, it is necessary to acquire reliable information of its mechanical properties at ambient and high temperatures for quantification of its fire resistance performance. This paper will present the results of experiments that have been carried out to examine and characterize the residual compressive strength of foamed concrete after high temperatures. Foamed concrete with 700 kg/m3 and 1000 kg/m3 density were cast and tested. The compression tests were carried out at ambient temperature, 100, 200, 300, 400, 500 and 600°C.

Influence of High Temperatures on the Mechanical Properties of Wood Bio-Concretes

2022 ◽  
Author(s):  
Amanda Lorena Dantas Aguiar ◽  
M’hamed Yassin Rajiv da Gloria ◽  
Romildo Dias Toledo Filho
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Temperatures ◽  
Room Temperature ◽  
Plant Biomass ◽  
Compression Tests ◽  
Wood Degradation ◽  
Cementitious Matrix ◽  
Wood Shavings ◽  
Temperature Reference

The use of wood wastes in the production of bio-concrete shows high potential for the development of sustainable civil construction, since this material, in addition to having low density, increases the energy efficiency of buildings in terms of thermal insulation. However, a concern arising from the production of bio-concretes with high amounts of plant biomass is how this material behaves when subjected to high temperatures. Therefore, this work aims to evaluate the influence of high temperatures on the mechanical properties of wood bio-concretes. The mixtures were produced with wood shavings volumetric fractions of 40, 50 and 60% and cementitious matrix composed of a combination of cement, fly ash and metakaolin. Uniaxial compression tests and scanning electron microscopy (SEM) were performed, with bio-concrete at age of 28 days, at room temperature (reference) and after exposure to temperatures of 100, 150, 200 and 250 °C. The density and compressive strength of the bio-concrete gradually decreased with increasing biomass content. Up to 200 °C, reductions in strength and densities less than 19% and 13%, respectively, were observed. At 250 °C, reductions of compressive strength reached 87%. Analysis performed by SEM showed an increase in the number of cracks in the wood-cementitious matrix interface and wood degradation by increasing the temperature.

COMPRESSIVE STRENGTH EVALUATION OF LIGHTWEIGHT CONCRETE WITH EXPANDED GLASS AGGREGATE BY ULTRASONIC PULSE VELOCITY METHOD

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Christopher Collins ◽  
Saman Hedjazi
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Normal Weight ◽  
Unit Weight ◽  
Normal Weight Concrete

In the present study, a non-destructive testing method was utilized to assess the mechanical properties of lightweight and normal-weight concrete specimens. The experiment program consisted of more than a hundred concrete specimens with the unit weight ranging from around 850 to 2250 kg/m3. Compressive strength tests were performed at the age of seven and twenty eight days. Ultrasonic Pulse Velocity (UPV) was the NDT that was implemented in this study to investigate the significance of the correlation between UPV and compressive strength of lightweight concrete specimens. Water to cement ratio (w/c), mix designs, aggregate volume, and the amount of normal weight coarse and fine aggregates replaced with lightweight aggregate, are the variables in this work. The lightweight aggregate used in this study, Poraver®, is a product of recycled glass materials. Furthermore, the validity of the current prediction methods in the literature was investigated including comparison between this study and an available expression in the literature on similar materials, for calculation of mechanical properties of lightweight concrete based on pulse velocity. It was observed that the recently developed empirical equation would better predict the compressive strength of lightweight concrete specimens in terms of the pulse velocity.

Effects of Fibre on Drying Shrinkage, Compressive and Flexural Strength of Lightweight Foamed Concrete

2012 ◽  
Vol 587 ◽  
pp. 144-149 ◽  
Author(s):  
Hanizam Awang ◽  
Md Azree Othuman Mydin ◽  
Ahmad Farhan Roslan
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Lightweight Concrete ◽  
Drying Shrinkage ◽  
Test Results ◽  
Polypropylene Fibres ◽  
Load Bearing ◽  
Foamed Concrete

The present study covers the use of fibre in lightweight foamed concrete (LFC) to produce the lightweight concrete for use in construction of non-load bearing elements. LFC with 600, 1000 and 1400 kg/m3 density were cast and tested. Polypropylene fibres with different percentage were used into LFC and the resulting products were compared to normal LFC. Compressive strength, flexural strength and drying shrinkage tests were carried out to evaluate the mechanical properties up to 180 days. The addition of fibres in LFC showed no contribution on compressive strength but improvement in the flexural and shrinkage test results.

scholarly journals Behavior of structural lightweight concrete produced with expanded clay aggregate and after exposure to high temperatures

2021 ◽  
Author(s):  
Rita Nemes ◽  
Mohammed A. Abed ◽  
Ahmed M. Seyam ◽  
Éva Lublóy
Keyword(s):  
Compressive Strength ◽  
High Temperatures ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Residual Compressive Strength ◽  
Concrete Mixtures ◽  
Temperature Exposure ◽  
Compaction Method ◽  
Do So

AbstractThe residual compressive strength of eight lightweight concrete mixtures containing three commercial grading (Liapor HD 5 N, Liapor HD 7 N, and Liapor 8F) of coarse lightweight aggregate (LWA) were determined after to expose at high temperatures. Eight mixes were produced, two by normal weight aggregate and the rest by different types of LWA. The produced concrete was analyzed after high temperature exposure and the effect of using LWA, the type of LWA, and compaction method was studied. To do so, visual inspection, residual compressive strength, crack pattern, spalling, and thermoanalytical analysis were conducted. Generally, it could be concluded that concrete formulations with LWA behave more advantageous up to 500 °C, compared to those with quartz gravel aggregates. Moreover, this study found that an ideal type of LWA to produce structural concrete was Liapor HD 5 N, which was used for producing the mixes L1 and L3.

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.

Preparation and Mechanical Properties of Polyethylene-Portland Cement Composites

2009 ◽  
Vol 1242 ◽  
Author(s):  
Rivas-Vázquez L.P. ◽  
Suárez-Orduña R. ◽  
Valera-Zaragoza M. ◽  
Máas-Díaz A. De la L. ◽  
Ramírez-Vargas E.
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Portland Cement ◽  
Plastic Waste ◽  
Cement Composites ◽  
Compression Tests ◽  
Standard Samples ◽  
Cement Ratio ◽  
Reinforcing Fibers ◽  
Waste Polyethylene

ABSTRACTThe effects of waste polyethylene aggregate as admixture agent in Portland cement at different addition polyethylene/cement ratios from 0.0156 to 0.3903 were investigated. The reinforced samples were prepared according the ASTM C 150 Standard (samples of 5 × 5 × 5 cm). The reinforcing fibers were milling at a size of 1/25 in diameter, form waste and used them to evaluate the effects in mechanical properties in cement-based composites. The evaluation of polyethylene as additive was based on results of density and compression tests. The 28-day compressive strength of cement reforced with plastic waste at a replacement polyethylene/cement ratio of 0.0468 was 23.5 MPa compared to the control concrete (7.5 MPa). The density of cement replaced with polyethylene varies from 2.114 (0% polyethylene) to 1.83 g/cm3 by the influence of polyethylene.

Deterioration of Mechanical Properties of High-Strength Pumpcrete after Exposure to High Temperatures

2010 ◽  
Vol 168-170 ◽  
pp. 564-569
Author(s):  
Guang Lin Yuan ◽  
Jing Wei Zhang ◽  
Jian Wen Chen ◽  
Dan Yu Zhu
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Heating Rate ◽  
High Strength Concrete ◽  
Heating Temperature ◽  
High Strength ◽  
Air Cooling ◽  
Test Results ◽  
Strength Deterioration ◽  
Residual Compressive Strength

This paper makes an experimental study of mechanical properties of high-strength pumpcrete under fire, and the effects of heating rate, heating temperature and cooling mode on the residual compressive strength(RCS) of high-strength pumpcrete are investigated. The results show that under air cooling, the strength deterioration speed of high-strength concrete after high temperature increases with the increase of concrete strength grade. Also, the higher heating temperature is, the lower residual compressive strength value is. At the same heating rate (10°C/min), the residual compressive strength of C45 concrete after water cooling is a little higher than that after air cooling; but the test results are just the opposite for C55 and C65 concrete. The strength deterioration speed of high-strength concrete after high temperature increases with the increase of heating rate, but not in proportion. And when the heating temperature rises up between 200°C and 500°C, heating rate has the most remarkable effect on the residual compressive strength of concrete. These test results provide scientific proofs for further evaluation and analysis of mechanical properties of reinforced-concrete after exposure to high temperatures.

scholarly journals Efficiency factor and modulus of elasticity of lightweight concrete with expanded clay aggregate

2010 ◽  
Vol 3 (2) ◽  
pp. 195-204 ◽  
Author(s):  
W.G Moravia ◽  
A. G. Gumieri ◽  
W. L. Vasconcelos
Keyword(s):  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
Large Scale ◽  
Lightweight Concrete ◽  
Weight Ratio ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Lightweight Aggregate Concrete ◽  
Empirical Methods ◽  
Normal Weight Concrete

Nowadays lightweight concrete is used on a large scale for structural purposes and to reduce the self-weight of structures. Specific grav- ity, compressive strength, strength/weight ratio and modulus of elasticity are important factors in the mechanical behavior of structures. This work studies these properties in lightweight aggregate concrete (LWAC) and normal-weight concrete (NWC), comparing them. Spe- cific gravity was evaluated in the fresh and hardened states. Four mixture proportions were adopted to evaluate compressive strength. For each proposed mixture proportion of the two concretes, cylindrical specimens were molded and tested at ages of 3, 7 and 28 days. The modulus of elasticity of the NWC and LWAC was analyzed by static, dynamic and empirical methods. The results show a larger strength/ weight ratio for LWAC, although this concrete presented lower compressive strength.

Research on Barite Concrete Mixed with Fly Ash

2013 ◽  
Vol 275-277 ◽  
pp. 2107-2111
Author(s):  
Qiu Lin Zou ◽  
Jun Li ◽  
Zhen Yu Lai
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Compressive Strength ◽  
High Temperature ◽  
Fly Ash ◽  
Apparent Density ◽  
Cycle Times ◽  
Residual Compressive Strength ◽  
Temperature Performance

Barite concrete with density grade of 3 and strength grade of C30 was prepared by mixing with different fineness of fly ash. The workability, mechanical properties and long-term high temperature performance of the prepared barite concrete were researched. Results show that the workability of barite concrete is improved by mixing with fly ash, and no segregation of mixture has been observed. The apparent density and 3d, 28d compressive strength of barite concrete are decreased obviously after mixing with fly ash. But with the increasing of the fineness of fly ash, the apparent density and 3d, 28d compressive strength of barite concrete have a slight increase. High temperature residual compressive strength is decreased with the increasing of temperature. The cycle times of heat treatment at 400°C only has a little effect on residual compressive strength of barite concrete.

scholarly journals Size Effect in Compressive Strength Tests of Cored Specimens of Lightweight Aggregate Concrete

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1187 ◽  
Author(s):  
Lucyna Domagała
Keyword(s):  
Compressive Strength ◽  
Scale Effect ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Cement Matrix ◽  
Lightweight Aggregate Concrete ◽  
Core Diameter ◽  
Aggregate Concrete ◽  
Normal Weight Concrete ◽  
Strength Tests

The aim of this paper is to discuss the unrecognized problem of the scale effect in compressive strength tests determined for cored specimens of lightweight aggregate concrete (LWAC) against the background of available data on the effect for normal-weight concrete (NWAC). The scale effect was analyzed taking into consideration the influence of slenderness (λ = 1.0, 1.5, 2.0) and diameter (d = 80, 100, 125, and 150 mm) of cored specimens, as well as the type of lightweight aggregate (expanded clay and sintered fly ash) and the type of cement matrix (w/c = 0.55 and 0.37). The analysis of the results for four lightweight aggregate concretes revealed no scale effect in compressive strength tests determined on cored specimens. Neither the slenderness, nor the core diameter seemed to affect the strength results. This fact should be explained by the considerably better structural homogeneity of the tested lightweight concretes in comparison to normal-weight ones. Nevertheless, there were clear differences between the results obtained on molded and cored specimens of the same shape and size.

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