添加飛灰與水淬爐石粉和爐石水泥混凝土抗硫防蝕性能試驗

Experiments: Sulfate Resistance and Anti-Corrosion for Concrete with Fly Ash, Granulated Blast-Furnace Slag and Slag Cement

本研究採用緻密配比模式，混凝土配比內添加不同細度水淬爐石粉(4302, 5651cm2/g)與F級飛灰ES(I)和爐石粉水泥(1:1)ES(M)與ES(H)，w/cm=0.40且拌合水量150kg/m3，拌製混凝土(坍度>230mm、坍流度>500mm、不泌水、不析離)，同時以Type II水泥與ACI配比法設計當作控制組CC(II)，澆置10×20cm試體，並在28天齡期時，以CNS 1167浸泡5000ppm及飽和硫酸鈉溶液的抗硫試驗;在91天齡期時，以ASTM C1202-97氯離子電滲試驗，測試硬固混凝土防蝕性能。試驗結果顯示，28天齡期，各配比抗壓強度大於35MPa，浸泡在5000ppm硫酸鈉溶，經過25次循環試驗，表面都無目視剝落或粉化損傷，重量損失在1%以內;浸泡在飽和硫酸鈉溶液時，各配比在不同試驗循環次數產生表面剝落，抗硫性能依序為ES(I) > ES(H) > ES(M) > CC(II)，重量損失達3%；氯離子電滲試驗顯示，緻密配比通過的電滲量都在1000庫倫以下，屬於"Very Low"以下的等級，防蝕性能甚優，而使用ACI配比設計並採用Type II水泥的CC(II)配比，氯離子電滲量8210庫倫，屬於"High"等級以上，抗腐蝕性能不佳；採用飛灰與磨細爐石粉、較低拌合水量有助提升混凝土抗硫防蝕性能。

This paper investigates two sets of concretes under attack from erosion solution of sulfate and chloride salt. One set is concrete produced by DMDA incorporating fly ash, different fineness of granulated blast-furnace slag(4561 and 5651 cm2/g), and slag cement(1:1). The other set is concrete by ACI 211.1 with Type II Portland cement. The development of strength and durability of concrete at workability and hardened states were also measured. W/cm(w/c) = 0.40 and mixing water 150 kg/m3, workability (slump> 230 mm, slump flow> 500 mm; no bleeding and segregation. The cement poured 10×20 cm specimens at 28 days, immersed in 5000 ppm and saturated sodium sulfate solution 24h, then oven-dried 24h at 105O C. At 25 cycles. At 91 days, the ASTM C1202 chloride ion penetrability was test. Results showed that the ratio of compressive strength was greater than 35 MPa at 28 days, immersed in 5000 ppm sodium sulfate solution and after 25 cycles of test surfaces was peeling or chalking there was -no visual damage, and weight loss was less than 1%. When immersed in a saturated sodium sulfate solution, the ratio of the different test cycles was flaking, sulfur resistance was ES (I)> ES (H)> ES (M)> CC (II), and weight loss was 3%. The chloride ion penetrability test showed that the charge passed less than 1000 coulombs. This "Very Low" level, illustrates it is an excellent anti-corrosion measure. Regarding Type II cement CC(II ), the chloride ion permeability was 8210 coulombs to illustrate its poor corrosion resistance was "High". The use of fly ash and finer ground slag particles coupled with lowering the mixing water enhanced resistance to sulfate attack and corrosion.