scholarly journals Effect of Moisture Content on the Behavior of High Strength Concrete at High Temperatures

2020 ◽  
Vol 25 (1) ◽  
Author(s):  
Larissa Degliuomini Kirchhof ◽  
Rogério Cattelan Antocheves de Lima ◽  
Almir Barros da Santos Neto ◽  
Alana Costa Quispe ◽  
Luiz Carlos Pinto da Silva Filho
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
High Strength Concrete ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
High Strength ◽  
Experimental Program ◽  
High Moisture ◽  
Strength Concrete ◽  
Normal Strength

ABSTRACT In this paper, an experimental program was carried out to investigate the residual mechanical properties of high strength concrete and normal strength concrete, and how moisture content and temperature affect the spalling process. Three mixtures with water-cementitious material ratios, from 0.25 to 0.50, and with different saturation levels were heated in an electric furnace to elevated temperatures, from 200°C to 600°C. After heating, the specimens were cooled down to room temperature and then tested for compression and tensile strength. The results showed that high moisture content induces the spalling process and reduces considerably the mechanical properties of high strength concrete, mainly at temperatures above 400°C.

Influences of Glassified Micro-Bubble on Mechanical Properties of Ultra-High-Strength Concrete after Exposure to High Temperature

2014 ◽  
Vol 629-630 ◽  
pp. 259-264
Author(s):  
Gai Fei Peng ◽  
Xiao Li Wang ◽  
Lin Wang
Keyword(s):  
Mechanical Properties ◽  
Experimental Investigation ◽  
High Temperature ◽  
High Strength Concrete ◽  
Room Temperature ◽  
High Strength ◽  
Strength Concrete ◽  
Micro Bubble ◽  
Residual Mechanical Properties ◽  
Tensile Splitting Strength

An experimental investigation was conducted to study residual mechanical properties of Ultra-High-Strength concrete with different dosages of glassified micro-bubble after exposure to high temperature. After exposure to different target temperatures (room temperature, 200 °C, 400 °C, 600 °C,800 °C), residual mechanical properties (residual compressive strength, residual tensile splitting strength, residual fracture energy) of Ultra-High-Strength concrete under different conditions including 1 water-binder ratios (0.18), 3 different contents of glassified micro-bubble (0%, 40%, 60%) were all investigated. The effect of different dosage of glassified micro-bubble was studied on residual mechanical properties of Ultra-High-Strength concrete after exposure to high temperature. The results indicate that the variations of different kinds of Ultra-High-Strength concrete with different dosage of glassified micro-bubble are basically the same. With the increase of temperature, the residual mechanical properties increase at first, then decrease. The residual mechanical properties decrease after exposure to high temperature of 800 °C.

Performance of high strength concrete-filled steel columns exposed to fire

1998 ◽  
Vol 25 (6) ◽  
pp. 975-981 ◽  
Author(s):  
VKR Kodur
Keyword(s):  
Fire Resistance ◽  
High Strength Concrete ◽  
High Strength ◽  
Experimental Program ◽  
Structural Behaviour ◽  
Steel Columns ◽  
Strength Concrete ◽  
Normal Strength ◽  
Concrete Filling ◽  
Hollow Structural Section

Results from an experimental program on the behaviour of high strength concrete-filled steel hollow structural section (HSS) columns will be presented for three types of concrete filling. A comparison will be made of the fire-resistance performance of HSS columns filled with normal strength concrete, high strength concrete, and steel-fibre-reinforced high strength concrete. The various factors that influence the structural behaviour of high strength concrete-filled HSS columns under fire conditions are discussed. It is demonstrated that, in many cases, addition of steel fibres into high strength concrete improves the fire resistance and offers an economical solution for fire-safe construction.Key words: high strength concrete, steel columns, fire-resistance design, high-temperature behaviour, concrete-filled steel columns.

Effect of different fiber types on the mechanical properties of normal and high strength concrete at elevated temperatures

2021 ◽  
Vol 12 (1) ◽  
pp. 30
Author(s):  
Mohamed Amin ◽  
Khaled Abu el-hassan
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
High Strength Concrete ◽  
Elevated Temperatures ◽  
Polypropylene Fiber ◽  
High Strength ◽  
Fiber Types ◽  
Strength Concrete ◽  
Compressive And Flexural Strengths ◽  
Fiber Addition

The effects of the types of fibers on mechanical properties of normal and high strength concrete under high temperature, up to 700 °C, was investigated. Three different- type fiber; "Steel Fiber (SF), Glass Fiber (GF) and Polypropylene Fiber (PPF)" are added into the concretes in five different ratios (0, 0.50, 1.00, 1.50 and 2.0%)of the volume under the following temperatures; 22, 100, 400 and 700°C. The results indicate that all the different types of fibers researched contribute to both the compressive and flexural strengths of concrete under high temperature, however, it is also found that this contribution decreases with an increase in temperature. The flexural strengths and compressive strengths for NSC and HSC mixes at 28 days under high temperature decreases as the temperature increases especially up to 400°C. Also, the best compressive and flexural strengths performance under high temperature was also those of SF. The compressive strength of the concrete incorporating SF was reduced under high temperature only, while the mixes containing PPF and GF were reduced under high temperature or with fiber addition. The optimum fiber addition ratios of the mixes containing PPF and GF are between 0.5-1.0 percent by volume. And for SF, it is 1.5% by the volume.

Residual Strength of Super High Strength Concrete Used Stone-Chip after Exposure to High Temperatures

2011 ◽  
Vol 374-377 ◽  
pp. 2456-2460
Author(s):  
Guo Can Chen ◽  
Zhi Sheng Xu ◽  
Wei Hong Tang
Keyword(s):  
High Temperatures ◽  
High Strength Concrete ◽  
Elevated Temperatures ◽  
Experimental Studies ◽  
High Strength ◽  
Normal Strength Concrete ◽  
Strength Concrete ◽  
Fine Aggregates ◽  
Normal Strength ◽  
Peak Value

This paper presents the results of experimental studies on the residual compressive strength of concrete produced with stone-chip as fine aggregates with the compressive strengths of unheated specimen ranging from 45.8 to 129.5MPa after exposure to high temperatures and the experimental parameters being the temperature, admixtures, and PP fiber. Specimens were heated in an electric furnace for 4h to high temperatures ranging from 150 to 960°C. Experimental results showed that the compressive strengths of super high strength concrete used stone-chip (abbreviated to SHSCUS) and normal strength concrete used stone-chip (abbreviated to NSCUS) after exposure to elevated temperatures changed in the manners different from that of normal strength concrete, which reached their peak at about 400°C, and the presence of pp fibers in SHSCUS concrete could reduce the risk of spalling at the high temperatures and the peak value after fire.

scholarly journals Behavior of High Strength Concrete Subjected to Elevated Temperature

2019 ◽  
Vol 9 (2) ◽  
pp. 2997-3000
Keyword(s):  
Compressive Strength ◽  
High Strength Concrete ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
High Strength ◽  
Air Cooling ◽  
Split Tensile Strength ◽  
Strength Concrete ◽  
Hardened Properties ◽  
Compressive Strength Of Concrete

The High strength concrete defined as per IS 456 as the concrete having characteristic compressive strength more than 65 MPa. The concrete when subject to fire i.e. elevated temperatures loses its properties at a rapid rate. In the present investigation, ordinary vibrated concrete of M90 grade was developed as per the IS 10262. The hardened properties of concrete like compressive strength and split tensile strength were determined for concrete at ordinary temperature. The concrete specimens were subjected to elevated temperatures of 400oC, 600 oC, and 800 oC and then the specimens were brought to room temperature under different cooling regimes like air cooling and water quenching. The compressive residual strength of concrete was determined and a typical compared was made with the control specimen. The decrease in compressive strength of concrete at 800 oC was high compared to that at 400 oC.

Investigation on Performance of Concrete Incorporating Silica Fume and Local UAE Materials

2019 ◽  
Vol 803 ◽  
pp. 222-227 ◽  
Author(s):  
Reem Sabouni ◽  
Hassan Raad Abdulhameed
Keyword(s):  
Mechanical Properties ◽  
Silica Fume ◽  
United Arab Emirates ◽  
High Strength Concrete ◽  
High Strength ◽  
Partial Replacement ◽  
Favorable Effect ◽  
Experimental Program ◽  
Strength Concrete ◽  
Local Materials

In an effort to reduce the amount of cement in the concrete industry and produce greener concrete, emphasis was put on using several industrial by-products such as silica fume, fly ash and slag as partial replacements for cement in concrete. Due to the enormous number of mega reinforced concrete projects constructed in the United Arab Emirates, it is considered to be one of the largest consumers of high strength concrete in the region. On the other hand, only limited research has been done on high strength concrete incorporating local materials in the UAE. The main objective of this research is to conduct an investigation on the performance of high strength concrete containing silica fume as partial replacement of ordinary Portland cement incorporating superplasticizers and local UAE materials by studying its mechanical properties and durability. The experimental program involved two groups: The first group had a water-to-binder material ratio (w/b) of 0.4, whereas, the second group had w/b = 0.3. For both groups the silica fume replacement percentages were 0 (control mix) 5, 7.5, 10, 12.5, and 15 percent. The mechanical properties were tested at 7, 28, and 91 days and the durability tests were performed at 28 days. The results were compared to the control mix and they showed that for all the curing ages studied the use of silica fume as partial replacement of OPC has favorable effect on the compressive strength values and the optimum replacement ratios of silica fume for the tested specimens are found to be at 12.5% and 10% replacement for the w/b ratios of 0.3 and 0.4, respectively. For all the four performed durability tests the replacement of the OPC with silica fume is found to have favorable results and the higher the silica fume percentage replacement of OPC the more favorable the results are. The detailed description of the used mixes and the main conclusions drawn from this research are presented in this paper

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