EXAMINATIONS OF THE INTERNAL STRUCTURE OF ZEOLITE-BLENDED CEMENTS

Öz

Pozzolans are mineral-based materials that are not cementitious on their own, but gain cementitious properties when they are combined with lime and cement and react with water. Studies are in rapid progress to enhance performance in concrete made with pozzolanic cements. In this experimental study, cement paste specimens of 40x40x160 mm were cured in water and then kept in MgSO4 solution to examine their 7- and 28-day compressive strengths and XRD and SEM images. An examination of the chemical and physical changes in the specimens cured in water and MgSO4 solution revealed that the specimens blended with 15% zeolite and containing superplasticizers had a slightly higher compressive strength than the specimens cured in MgSO4 solution. This points out to the high pozzolanic activity and to the fact that 15% admixture rate made zeolite-blended specimens resistant against MgSO4 solution. Consequently, zeolite is converted into Calcium Silicate Hydrate (C-S-H) composites after binding the portlandite, Ca(OH)2, content in cement. Therefore, it could be argued that cements prevent corrosion, decrease the permeability of concrete, and improves its resistance against sulfate environments. The most characteristic aspect of the study is that the specimens were placed in MgSO4 solution on the 1st day. In this work, images which have different frame length are modeled by KLT (Karhunen Loeve Transform). PSNR is used as the performance criteria. It has been shown that, short frame length performs better than long frame length in image data compression.

Anahtar Kelimeler

• Cement, Puzzolan, SEM, XRD, Zeolite

Kaynakça

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