scholarly journals ANALISIS MANFAAT BIAYA PENGELOLAAN LIMBAH SPENT BLEACHING EARTH MELALUI PEMANFAATAN DAN PENIMBUNAN DENGAN MEMPERHITUNGKAN NILAI GAS RUMAH KACA

2017 ◽  
Vol 23 (2) ◽  
pp. 33-42
Author(s):  
Kapas Fernando Pasaribu ◽  
◽  
Sukandar Sukandar ◽  
Keyword(s):  
2009 ◽  
Vol 46 (2) ◽  
pp. 176-180 ◽  
Author(s):  
Enos W. Wambu ◽  
Gerald K. Muthakia ◽  
Joseph K. wa-Thiong'o ◽  
Paul M. Shiundu

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2967
Author(s):  
Rokiah Othman ◽  
Ramadhansyah Putra Jaya ◽  
Khairunisa Muthusamy ◽  
MohdArif Sulaiman ◽  
Youventharan Duraisamy ◽  
...  

This study aims to obtain the relationship between density and compressive strength of foamed concrete. Foamed concrete is a preferred building material due to the low density of its concrete. In foamed concrete, the compressive strength reduces with decreasing density. Generally, a denser foamed concrete produces higher compressive strength and lower volume of voids. In the present study, the tests were carried out in stages in order to investigate the effect of sand–cement ratio, water to cement ratio, foam dosage, and dilution ratio on workability, density, and compressive strength of the control foamed concrete specimen. Next, the test obtained the optimum content of processed spent bleaching earth (PSBE) as partial cement replacement in the foamed concrete. Based on the experimental results, the use of 1:1.5 cement to sand ratio for the mortar mix specified the best performance for density, workability, and 28-day compressive strength. Increasing the sand to cement ratio increased the density and compressive strength of the mortar specimen. In addition, in the production of control foamed concrete, increasing the foam dosage reduced the density and compressive strength of the control specimen. Similarly with the dilution ratio, the compressive strength of the control foamed concrete decreased with an increasing dilution ratio. The employment of PSBE significantly influenced the density and compressive strength of the foamed concrete. An increase in the percentage of PSBE reduced the density of the foamed concrete. The compressive strength of the foamed concrete that incorporated PSBE increased with increasing PSBE content up to 30% PSBE. In conclusion, the compressive strength of foamed concrete depends on its density. It was revealed that the use of 30% PSBE as a replacement for cement meets the desired density of 1600 kg/m3, with stability and consistency in workability, and it increases the compressive strength dramatically from 10 to 23 MPa as compared to the control specimen. Thus, it demonstrated that the positive effect of incorporation of PSBE in foamed concrete is linked to the pozzolanic effect whereby more calcium silicate hydrate (CSH) produces denser foamed concrete, which leads to higher strength, and it is less pore connected. In addition, the regression analysis shows strong correlation between density and compressive strength of the foamed concrete due to the R2 being closer to one. Thus, production of foamed concrete incorporating 30% PSBE might have potential for sustainable building materials.


1963 ◽  
Vol 12 (9) ◽  
pp. 528-531
Author(s):  
Tetsutaro HASHIMOTO
Keyword(s):  

2012 ◽  
Vol 61 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Masao Shimizu ◽  
Junya Moriwaki ◽  
Daisuke Shiiba ◽  
Hidenori Nohara ◽  
Naoto Kudo ◽  
...  
Keyword(s):  

2011 ◽  
Vol 174 (1) ◽  
pp. 275-280 ◽  
Author(s):  
M. Mana ◽  
M.S. Ouali ◽  
L.C. de Menorval ◽  
J.J. Zajac ◽  
C. Charnay
Keyword(s):  

2012 ◽  
Vol 30 (1) ◽  
pp. 97-104 ◽  
Author(s):  
Müsęerref Önal ◽  
Yüksel Sarıkaya

The optimum conditions necessary for preparing a bleaching earth (BE) with maximum bleaching power (BP) towards soybean oil (SO) and cottonseed oil (CSO) were investigated. BEs were obtained by H2SO4 activation of a white calcium bentonite (CaB) sample from the Kütahya region of Turkey. After drying for 4 h at 105 °C, the CaB samples were activated by heating their acidic aqueous suspensions for 6 h at 97 °C, the acid content of the dry bentonite/acid mixture being varied in the 0–70% mass range. The respective specific surface area (S) and specific nanopore volume (V) of the BEs were determined from nitrogen adsorption/desorption data obtained at −196 °C. For natural CaB, the values of S and V were 44 m2/g and 0.11 cm3/g, respectively. These values attained a maximum of 135 m2/g and 0.30 cm3/g for the BE sample prepared employing 40% H2SO4 for acid activation. Interestingly, the maximum BP was not associated with the maximum S and V values. The optimum values for the percentage H2SO4, S and V for attaining the maximum BP were 20%, 100 m2/g and 0.17 cm3/g, respectively. The mean nanopore radius (r) of each BE was calculated using the corresponding S and V values. Nanopores with a mean radius in the range 3.5–5.5 nm, which was close to the diameter of the coloured pigment, were found to be mostly responsible for the BP towards SO and CSO. The results obtained in the present study indicate that the value of r was more effective than the S and V values of BEs in the bleaching of vegetable oils. Adsorption of a pigment onto a BE was found to depend not only on the physicochemical interaction between the pigment molecule and the BE surface, but also on the mean nanopore size.


2011 ◽  
Vol 170 (1) ◽  
pp. 90-106 ◽  
Author(s):  
Farihahusnah Hussin ◽  
Mohamed Kheireddine Aroua ◽  
Wan Mohd Ashri Wan Daud

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