Estimating Deterioration Rate of Some Carbonate Rocks Used as Building Materials under Repeated Frost Damage Process, China

Table 4

Mean and standard deviation (SD) of Schmidt hammer rebound (Sch) values before and after frost cycles.

Cycles	Fresh		10		20		30		40		50
	Mean	SD	Mean	SD	Mean	SD	Mean	SD	Mean	SD	Mean	SD
Limestone 1	55.1	2.2	54.7	2.4	54.2	2.1	53.6	2.9	52.9	1.7	52.4	2.0
Limestone 2	52.7	2.6	51.8	2.2	51.1	1.9	50.6	2.0	49.9	1.7	49.3	2.1
Limestone 3	38.4	1.3	37.8	1.4	36.9	0.9	36.2	1.1	35.0	1.6	34.3	1.8
Limestone 4	43.2	1.8	42.5	1.6	42.0	1.7	41.4	1.9	40.8	2.2	40.1	2.3
Limestone 5	49.8	2.0	49.0	2.1	48.2	2.4	47.6	1.8	46.5	2.3	45.7	1.9
Limestone 6	34.0	0.8	33.3	0.9	32.5	1.1	31.7	1.3	31.0	1.0	30.3	1.4