03916nas|a2200385 i 4500 20260818090359.0 220900s2000 th uzm rtt 00| a1eng d .b11809553 AIT Thesis no.ST-00-33 Mahbub-Ul-Alam, Md. Deterioration of concrete due to weak-acid attack Bangkok : Asian Institute of Technology, 2000 61 leaves Thesis ; no. ST-00-33 A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Civil Engineering Thesis (M.Eng.) - Asian Institute of Technology, 2000 Generally, concrete becomes deteriorated under acidic attack. In this research, to investigate this response of concrete to weak acids, an accelerated Laboratory Test Program was conducted considering the different influencing factors such as different levels of pH (2, 3, 4 & 5) water/cement ratios (60% & 80%), temperatures of acid solution (25°C & 50°C), types of cement etc. Test specimens consisted of standard concrete cylinders having a diameter of 10 cm and a height of 20 cm. The total number of the specimens (with and without reinforcement) were one hundred and fifty two, made by using Ordinary Portland cement and 30% Fly ash cement, crushed limestone as coarse aggregate and river sand. All these specimens were immersed in acidic solutions, having different pH levels respectively, for three months. To accelerate the effect, two days drying (humidity=60%) and three days immersion (humidity=95%) was conducted cyclically during whole exposure periods. During and after continuous accelerated exposure test, all specimens were tested to investigate their change in color, size, weight and compressive strength. The reinforced specimens were examined to check the effect of acidic solutions on corrosion of reinforcing bars. Test results showed that fly ash cement Concrete (herein after called "FACC") specimen had better resistance to corrosion of steel bars compared to the ordinary Portland cement concrete (herein after called "OPCC") specimen. In strong acid, OPCC specimens lost less weight than FACC whereas in weak acids FACC specimens found better to use due to less reduction in surface materials. Both types concrete specimens got change in their color during exposure test in pH=2 and 3 of the acid solutions. In other weak acid having pH=4, more color change occurred in case of FACC compared to OPCC. During 91-days exposure period, FACC specimens showed the increasing rate of compressive strength from 28-days one to higher in both strong and weak acids whereas this strength of OPCC specimens in the solutions having pH=2 & 3, fall down in exposure periods than 28-days compressive strength. The overall test results indicated that FACC specimen is less effective to deterioration of concrete under weak acidic environment compared to OPCC. Concrete Deterioration Takewaka, Koji, Chairperson Pichai Nimityongskul, Examination Committee Nii, Kazuyoshi, Examination committee Government of Japan, Scholarship donor Asian Institute of Technology. Thesis ; no. ST-00-33 Full-Text http://203.159.5.9/ait-thesis/detail.php?q=B06858 .b11809553 mnait u 240331 0 000922 m a u 0 mnait mnarc 22 40 Barcode : 30050120746978 CREATED : 2014-05-20 RECORD # : i12801586 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 Barcode : 30050160102330 CREATED : 2016-04-21 RECORD # : i12943484 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 27906 27906 0 0 0 0 MAIN MAIN mnait 2026-08-18 50.00 0 AIT Thesis no.ST-00-33 30050120746978 2026-08-18 09:03:59 3 2026-08-18 22 0 0 0 0 MAIN MAIN mnarc 2026-08-18 0 AIT Thesis no.ST-00-33 30050160102330 2026-08-18 09:03:59 1 2026-08-18 40