Table 4.

Diameter variations of GFRP rebars subjected to direct immersion in the alkaline solution.

Temperature	Type of Rebar	Measure No.	Diameter Variation (%)
			30 Days	60 Days	90 Days	120 Days
20 °C	Sand-coated	1	−2.84	−0.43	−2.84	−2.84
		2	−0.72	1.73	−2.88	−3.45
		3	−1.43	2.50	−3.93	−2.29
		Mean	−1.7 ± 0.9	1.3 ± 1.3	−3.2 ± 0.6	−2.9 ± 0.5
	Non-coated	1	1.79	−0.81	−0.81	−0.57
		2	1.63	−0.24	−0.65	−1.22
		3	2.54	0.66	0.41	0.25
		Mean	2.0 ± 0.4	−0.1 ± 0.6	−0.4 ± 0.6	−0.5 ± 0.6
40 °C	Sand-coated	1	−1.42	−0.64	−4.61	−5.18
		2	−2.14	0.00	−5.71	−4.29
		3	−6.12	−4.22	−7.21	−3.40
		Mean	−3.2 ± 2.1	−1.6 ± 1.9	−5.9 ± 1.1	−4.3 ± 0.8
	Non-coated	1	0.81	−1.61	−2.02	−1.69
		2	1.63	−1.22	−0.41	−0.81
		3	1.87	−1.06	−1.06	−0.81
		Mean	1.4 ± 0.5	−1.3 ± 0.3	−1.2 ± 0.7	−1.1 ± 0.5
60 °C	Sand-coated	1	−1.45	1.38	−2.90	−1.09
		2	−3.62	−0.51	−3.99	−2.17
		3	−0.73	0.36	−2.19	−3.28
		Mean	−1.9 ± 1.3	0.4 ± 0.8	−3.2 ± 0.8	−2.2 ± 0.9
	Non-coated	1	2.46	−0.33	0.82	0.16
		2	1.30	−1.14	1.63	−0.57
		3	−0.87	−3.57	−1.59	−1.90
		Mean	1.0 ± 0.4	−1.7 ± 1.4	0.3 ± 1.4	−0.8 ± 0.9