International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 09 Issue: 05 | May 2022
p-ISSN: 2395-0072
www.irjet.net
Petrographic investigation to assess condition of concrete exposed to fire Mr. Nikhil k. patil1, Ass. Prof. S.P. Patil2 1M-Tech
(Student), Sanjay Ghodawat University, Kolhapur Professor, Civil Engineering Department, SGU, Kolhapur. ---------------------------------------------------------------------***--------------------------------------------------------------------2Ass.
Abstract - The durability properties of concrete after
exposed to different temperature were studied in this paper. The results of durability property tests exposed to varying degrees of temperature indicate that the cement quantity, water cement ratio, and cooling type are the most important elements influencing the residual strength of concrete. Concrete specimens were heated to 200°C, 400°C, 600°C, and 800°C in an electric boogie furnace. The specimens were then allowed to cool naturally (gradual cooling) . To determine durability properties, the Rapid chloride permeability test performed. According to test result, the structure of the interior pores and micro cracks has a big impact on the proportion of chloride ions that get into the concrete sample. Due to significant cracking, the RCPT values of all the concrete mixes after being exposed to a high temperature of 800°C were more than 400 C.
1. INTRODUCTION Because fire affects the structural integrity of concrete structures, it remains one of the most significant potential threats. Concrete's physical, strength, and serviceability properties are all negatively affected by fire. As a result, it's crucial to investigate the fire resistance of concrete. The cause of this phenomena is concrete's limited heat conductivity at high temperatures, which restricts the depth of fire damage penetration. Concrete does not produce harmful flames during a structure fire. The most serious issue in a building fire is public safety. Codes and standards describe the fire protection requirements for structural members in terms of fire resistance ratings based on tests performed according to predetermined standard procedures. In unheated concrete specimens, increasing the water-tocement ratio reduced compressive strength, however in heated specimens, a greater water-to-cement ratio resulted in less compressive strength reduction. Furthermore, the pace at which concrete weakens when subjected to high temperatures is dependent on the rate of heating. Because water evaporates slowly, no reduction in strength was detected when concrete specimens were gently heated between 100 and 200°C. However, a rapid increase in the rate of heating causes a rise in vapour pressure, which can |
Impact Factor value: 7.529
2. Preperation and casting 2.1 Material Used Throughout the experiment, ordinary Portland Cement (OPC) of grade 53 is utilized. All properties of cement are tested by referring IS 12269-1987. Fineness of cement is 1.33%. Standard consistency of cement paste is 32%. Hence the sample of cement tested so, as found out to be satisfactory according to IS 12269-1987. As a fine aggregate, locally accessible river sand with specific gravity 2.75 has been used and coarse aggregates with a size of 20 mm having specific gravity 2.96 were used.
Key Words: temperature, durability properties, rcpt
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lead to concrete cracking. Furthermore, the majority of the study on the residual qualities of concrete after a fire was conducted under natural air-cooling circumstances. The circumstances during a fire and natural air cooling appear to be distinct from the cooling regimes in a real fire, when
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Armixplast 111 admixture is used. It is supplied as a brown colour liquid. It has been particularly prepared to provide excellent workability or to generate high-quality concrete with lower permeability and improved density. The laboratory tap water was used. 2.1 Mix design for M30 grade concrete Mix design for M30 grade concrete is done as per IS 102622009. The table shows the mix design for M30 grade concrete. Table 1. Mix proportion Weight
W/c ratio
Cement
Fine aggregate
Coarse aggregate
Ratio
0.45
1
2.14
4.185
Kg/m3
153
340
728.45
1422.9
2.2 Casting All the specimens were prepared in accordance with Indian Standard Specification IS 516-1959. Prepare the test sample of concrete of dimension 50 mm thickness 100 mm diameter for the purpose of testing for determining permeability. ISO 9001:2008 Certified Journal
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