Quantitative Analysis of Portland Cement Clinker with Rietveld Refinement: Implications of the Amorphous Matter

Six ordinary Portland cement (OPC) clinkers and one white cement clinker were analyzed with the Rietveld method, using ZnO internal standard (IC), to determine the presence of amorphous matter (AM). All clinkers contain abundant AM and have lower silicate phase contents when compared with the same clinkers analyzed without IC, whereas the abundances of the aluminate and ferrate phases were not affected by AM. The white cement clinker had the highest AM content. Determination of AM is important for complete characterization of the OPC clinker and might contribute to a better understanding of the mechanical properties of the clinker.

IMPROVING THE VOLUMETRIC STABILITY OF WHITE CEMENT BY USING SOME ADDITIVES

This study looked at the effects of three types of additives: limestone powder, Arabian gum AG, and polyvinyl alcohol (PVA), on White Cement Mortar's Physical and Mechanical Properties the mixing ratio for dry shrinkage was 1:2. (Cement: sand) while for other tests, it was 1:2.75 (cement: sand). The limestone powder proportions are (5%, 10%, and 15%) by weight of white cement, while the AG ratios are (0.2, 0.5, and 0.8) % by weight of white cement, the polyvinyl alcohol ratios are (2%, 4%, and 6%). This study was focused at the compressive and flexural strength of the modified mortar, as well as water absorption and drying shrinkage. According to the findings, utilizing of limestone powder as additive in white cement mortar is not advised. Since it had the negative affect on dry shrinkage of the mortar. Furthermore, polymer additives such as AG and PVA significantly increase the reduction of ability of forming crack in white cement mortar. Furthermore, the optimal additive percentages of AG and PVA are 0.5 percent and 6%, respectively.

Fabrication and Characterization the Properties of Decorative Tile from White Cement and Waste Glass Powder

This research mainly focused on the properties of decorative white cement tiles which made from waste glass and white cement. The ratio of waste glass powder and white cement were studied at 10 : 90, 15 : 85, 20 : 80, 30 : 70, 40 : 60, 50 : 50, 60 : 40 and 70 : 30 by using water content at 30 %wt. All components were mixed and cast into the mould. Decorative white cement tiles were curing at 14, 21 and 28 days. In order to characterize physical and mechanical properties, all tiles were measured density, water absorption and compressive strength. According to the results, it can be obviously seen that density increased and water absorption decreased with increasing waste glass powder content. The highest compressive strength of around 36.5 MPa was found at 20 %wt of waste glass powder. However, compressive strength decreased with increasing waste glass powder over 20 %wt (waste glass powder 20: white cement 80). It was found that the lowest compressive strength of around 30.58 MPa was found at 70 %wt of waste glass powder. Curing time also affected properties as it was found that increasing curing time to 28 days resulted in increasing of density and compressive strength. In order to study how long does essential oil last on decorative white cement tiles, the orange essential oil at 1, 5 and 10 %wt were added into the white cement paste by using waste glass powder : white cement at 20 : 80 with 30 %wt of water. Decorative white cement tiles were smelled by 30 people every morning for 30 days and it can be found that 10 %wt of orange essential oil last longest on the decorative white cement tiles with 22 days.

RESEARCH OF THE POSSIBILITY OF REDUCING THE CIRCULATION OF SULFUR OXIDE IN THE PRODUCTION OF WHITE CEMENT

The article discusses the possibility of reducing the circulation of sulfur oxide in the production of white cement by introducing alkaline potassium oxides K2O and sodium Na2O. A decrease in the circulation of sulfur oxide SO3 is achieved by increasing its yield in the clinker by transferring SO3 from a more sublimated compound of calcium sulfate CaSO4 to less sublimated potassium sulfates K2SO4 and sodium Na2SO4. Potassium and sodium oxides are introduced in the composition of carbonates and feldspar. The amount of introduced alkali oxides is controlled by the molar ratio A/S between sulfur oxide SO3 and alkaline oxides K2O and Na2O. It is shown that with the same molar ratio between sulfur oxide and alkaline oxides, the amount of SO3 removed with clinker depends on the ratio between potassium and sodium oxides. The higher the sodium oxide content, the more sulfur oxide comes out with the clinker and less remains to circulate in the kiln. The sublimation of sulfur oxide decreases from 70.5% - without the introduction of alkaline oxides, to 38,5 % at the maximum A/S ratio with the addition of potassium and sodium oxides in a ratio of 80:20 %. When potassium and sodium oxides are added in a ratio of 20:80%, the sublimation of sulfur oxide is reduced to 7,7 % at the same A/S ratio.

Effect of Grey and White Portland Cement Fillers on Flexural and Shear Strength of GFRP Composite Material

The mechanical behaviour of glass fiber reinforced polymer (GFRP) composite depends on the type of matrix, filler, and fiber architecture. In order to develop high-strength polymer matrix composites, the composites containing 5%, 10%, and 15% each of Portland grey and white cement filler are prepared by uniformly mixing the epoxy and filler materials, followed by casting by hand layup technique. The flexural and shear test is performed in accordance with ASTM 790 and ASTM D5379, respectively. It has been found that the values of shear strength, flexural strength, and modulus of elasticity vary with the increasing amount of cement component in the polymer. In addition, for a given percentage of the components of the cementitious filler, the values of the mechanical strength of the composites that contain white cement are higher than those of the composites that contain grey cement filler. Damage to composites has been found to involve fiber breakage and delamination primarily.

Experimental Investigation of Traditional Clay Brick and Lime Mortar Intended for Restoration of Cultural Heritage Sites

To properly restore masonry cultural heritage sites, the materials used for retrofitting can have a critical effect, and this requires standards for traditional Korean brick and lime mortar to be examined. This study experimentally investigated the material characteristics of Korean traditional bricks and two types of lime mortar (quicklime lumps and powdered hydrated lime) and the strength of masonry specimens made from those materials. Four different mixing ratios of lime, sand and white cement were considered as material parameters in this study. The experiment included uniaxial compressive testing and flexural testing to examine the mortars’ mechanical properties, and compression tests, triplet shear tests and diagonal compression tests for the masonry specimens. The results found that the strength of the masonry specimens was not necessarily associated with the mortar’s strength, but rather the cohesion between brick and mortar. In the material test, adding white cement had no noticeable effect on mortar strength. Meanwhile, in the masonry specimen, the effect of the added white cement was significant in terms of compressive and shear strength. This suggests that the bonding ratio between mortar and brick, which is an important factor influencing the behavior of bricks, was stronger with the addition of white cement. Furthermore, it was found that quicklime lumps had a lower strength than powdered hydrated lime. The test specimen with white cement added to powdered hydrated lime exhibited the greatest strength.

Perbandingan metode Double Exponential Smoothing dan Simple Moving Average pada kasus peramalan penjualan

Barokah Building Shop (TB. Barokah) located in Singosari, Malang, East Java is one of the shops that sells building materials. Some of the items being sold are white cement and black cement. The number of cement sales every month is very diverse and fluctuating. Black cement occupies a very high number compared to black cement on the sales chart every month. Likewise with the black cement from the Bosowa brand, white cement from the Gresik brand and the Tiga Roda brand, although demand is small, there is still a movement in the number of sales. The fluctuating amount of demand made the amount of product inventory prepared uncertain, which was influenced by the number of types and brands, so that the product inventory management had difficulty in supplying it. This study aims to predict the amount of cement sold in the following month, as well as to determine the performance between the two double exponential smoothing (DES) methods and the simple moving average (SMA) to forecast cement sales results in TB. Barokah. The SMA method is able and can perform forecasts with stable/constant demand or sales data. Meanwhile, the DES method is able and can provide values to the stratified weights with up to date data. DES is capable of forecasting cement sales each month with an average percentange error (PE) of 0.14%, while the SMA is with an average PE value of 1.35%. Based on the test results using data from TB. Barokah found that the most effective method is DES because it has a smaller PE value than the SMA.