بررسی نقش لاتکس پلیمری در عملکرد بتن تعمیری در شرایط محیطی منطقه خلیج فارس

Earlier laboratory work by the authors indicated satisfactory performance of glass powder (GLP) in concrete as a pozzolanic material. In order to investigate the performance of GLP in concrete under field conditions, a field trial was conducted using a 40 MPa concrete mix, incorporating various proportions of GLP (0, 20, and 30%) as cement replacement. Ten mix formulations were used to cast ten concrete slabs (1.5 × 2.5 × 0.25 m). Cylinders and prisms were also manufactured at the time of casting for the measurement of compressive and splitting tensile strength, shrinkage, expansion, ultrasonic pulse velocity, volume of permeable voids, etc. Core samples were drilled from the slabs at various ages for the same tests. Strength results showed that at 28 days the reference mixes and only the mix containing 20% glass powder had met the strength requirement for 40 MPa concrete, whereas at 90 days and later ages the mix containing 30% glass powder had also caught up in strength. This indicated further strength development due to pozzolanic reaction. The strength of some cores drilled from the trial slabs was considerably lower than those of corresponding laboratorycured cylinders, and this has been attributed to inadequate compaction. The flexural strength of concrete largely followed the same trend as the compressive strength. The mixes performed satisfactorily with respect to drying shrinkage and alkali reactivity, and there were indications that GLP reduces the chloride ion penetrability of the concrete, thereby reducing the risk of chloride induced corrosion of the steel reinforcement in concrete. The results have demonstrated that GLP can be incorporated into 40 MPa concrete mixes at 20- 30% to replace cement without harmful effects. The rate of strength gain is slower in GLPbearing concrete compared to the control mixes, but the final strength is well above the 40 MPa target. The use of GLP provides for considerable utilisation of waste glass in concrete and significant reductions in the production of green house gases by the cement industry.

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بتن تعمیری اصلاح شده با مواد پلیمری , استایرن بوتادی ان رابر , میکروسیلیس , شرایط محیطی گرم و مرطوب , خرابی سازه های بتنی مسلح