Test methodology for determining the mechanical properties of concrete blocks at high temperatures

The fire behavior of a structural masonry building has a positive relationship with the behavior of its constituent materials under high temperatures. Assessing the residual mechanical strength of the structural masonry components is essential, following the exposure to high temperatures. This work proposes to examine the standard for the determination of the mechanical properties (compressive strength and elastic modulus) of concrete blocks under high temperatures. Based on the existing recommendations (RILEM Technical Committee in Mater Struct 40: 841–853, 2007. 10.1617/s11527-007-9285-2, Mater Struct 40: 855–864, 2007. 10.1617/s11527-007-9286-1, Mater Struct 28: 410–414, 1995, Mater Struct 33: 219–223, 2000, Mater Struct 37: 139–144, 2004. 10.1007/bf02486610, Mater Struct 30: 17–21, 1997. 10.1007/bf02539270, Mater Struct 31: 290–295, 1998, Mater Struct 33: 6–13, 2000, Mater Struct 33: 224–228, 2000, Mater Struct 38: 913–919, 2005. 10.1617/14363RILEM Technical Committee (2007), Recommendation of RILEM TC 200-HTC in Mater Struct 40: 449–458, 2007. 10.1617/s11527-006-9203-z), an extensive experimental program was proposed to guide the adaptation of these recommendations to the case of concrete blocks, with emphasis on the heating and cooling rate of the samples. Suggestions of parameters necessary for laboratory evaluation of residual mechanical strength at elevated temperatures are presented for the hollow concrete block (HCB): number of specimens, testing age, storage conditions, rate of temperature rise with the time for heating the samples, suggestions of internal instrumentation of the equipment for the effective control of this rate and guaranteeing uniformity of heating.