Effects of plasticizer and antifreeze on concrete at elevated temperatures and different cooling regimes

Abstract

In recent years, chemical admixtures have become one of the main components of concrete alongside aggregate, cement and water. In this study, the plasticizer and the antifreeze were used. The concrete specimens (the reference concrete without an admixture, concrete with plasticizer, concrete with antifreeze and concrete with plasticizer+antifreeze) were exposed to elevated temperatures (200, 400, 550 and 700 ºC) and cooling via air and water. Water absorption, ultrasonic pulse velocity and compressive strength tests were performed on the specimens. The concrete specimens were also analyzed using X-ray diffraction. The test results indicated that at the temperatures of 550 and 700 ºC and against both of the cooling regimes the plasticizer+antifreeze concrete showed a maximum strength loss. When the air cooled specimens were examined, the lowest strength loss was this obtained for reference concrete at 550 and 700 ºC. The lowest strength loss at these temperatures for the water cooled specimens was observed in the concrete with antifreeze. After being exposed to 700 ºC and the cooling regimes, no portlandite peaks were observed in the concrete mixtures was when they were compared at with the control specimen exposed to 20 ºC in the X-ray diffraction analysis.

Effects of High Temperature and Cooling Regimes on Properties of Marble Powder-Based Cementitious Composites

“…These conditions menti in the literature can explain the significant decrease in UPV values observed for sam exposed to temperatures of 600 and 800 °C. Overall, the UPV findings for samples co in air and water are consistent with the findings of previous literature studies [50,51] ditionally, it has been reported that UPV results are related to pore structure and sa…”

“…Topcu and Demir [49] have also reported that the breakdown of the C-S-H gel at temperatures above 450 • C reduces the speed of sound wave propagation and hence decreases UPV values. These conditions mentioned in the literature can explain the significant decrease in UPV values observed for samples exposed to temperatures of 600 and 800 • C. Overall, the UPV findings for samples cooled in air and water are consistent with the findings of previous literature studies [50,51]. Additionally, it has been reported that UPV results are related to pore structure and sample density and that there is a relationship between mechanical properties and UPV results [17,52].…”

“…For the mortar samples exposed to temperatures of 300 • C, 600 • C, and 800 • C, the relative residual U w percentages were found to be in the ranges of 95.87-96.81%, 90. 51 The Uw values of samples cooled with water after exposure to high temperatures are presented in Figure 5. The Uw values of mortar samples cooled with water after high-temperature exposure were lower than those of samples tested in the laboratory environment (20 °C).…”

Experimental Evaluation of New Geopolymer Composite with Inclusion of Slag and Construction Waste Firebrick at Elevated Temperatures

“…There are various types of cooling, such as air and water. Kara and Arslan [42] investigated the high-temperature effect of plasticizer and antifreeze additives on cementitious composites. They found that the decrease in strength was the highest in the mixtures where plasticizer and antifreeze were used together for both cooling types at temperatures of 550 • C and 700 • C. In contrast, the lowest strength decrease was obtained from the samples with antifreeze added to the water cooler.…”