| 英文摘要 |
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. |
