scholarly journals Durability and Strength Characteristics of Casein-Cemented Sand with Slag

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3182
Author(s):  
Sung-Sik Park ◽  
Seung-Wook Woo ◽  
Sueng-Won Jeong ◽  
Dong-Eun Lee

Casein is often used as an eco-friendly wood adhesive. In this study, we used casein for soil cementation by mixing it with Jumunjin sand, sodium hydroxide (SH), and calcium hydroxide (CH) as a standard casein formula. The modified casein binder with different proportions of SH and CH was applied to improve water resistance. Furthermore, a blast furnace slag (BFS) was additionally mixed and reacted with alkalinity of modified casein binder. Thus, three types (standard, modified, and modified + BFS, referred to as STD, MOD, and MBS, hereafter) of casein binders were tested for durability and strength of casein-cemented sand. A piezoelectric sensor was installed within each sample to determine the curing time of the casein-cemented samples. The samples were air-cured at room temperature for seven days and some were repeatedly immersed in water thrice. Unconfined compression and jar slake tests were carried out to evaluate the strength and durability of the casein-cemented sand. Also, the microstructure was analyzed using a scanning electron microscope (SEM). We observed variations of peak conductance and corresponding frequency converged as the curing time increased. It was most significant for the MBS samples, which developed strength early. The unconfined compressive strength (UCS) of the air-cured samples was higher than those repeatedly immersed in water due to wash-off of the casein binder. The UCS of the dry MBS sample was 9900 kPa while that of the immersed sample was 430 kPa, which gradually decreased to 60 kPa upon repeated immersion. The samples with STD and MOD had no resistance to durability and showed cracks on the surface, while the MBS sample exhibited significantly improved durability and no cracks. We found that the MBS binder had a positively significant effect on the durability and strength of casein-cemented sand.

2021 ◽  
Vol 7 (3) ◽  
pp. 32
Author(s):  
Noorina Hidayu Jamil ◽  
Mohd. Mustafa Al Bakri Abdullah ◽  
Faizul Che Pa ◽  
Mohamad Hasmaliza ◽  
Wan Mohd Arif W. Ibrahim ◽  
...  

The main objective of this research was to investigate the influence of curing temperature on the phase transformation, mechanical properties, and microstructure of the as-cured and sintered kaolin-ground granulated blast furnace slag (GGBS) geopolymer. The curing temperature was varied, giving four different conditions; namely: Room temperature, 40, 60, and 80 °C. The kaolin-GGBS geopolymer was prepared, with a mixture of NaOH (8 M) and sodium silicate. The samples were cured for 14 days and sintered afterwards using the same sintering profile for all of the samples. The sintered kaolin-GGBS geopolymer that underwent the curing process at the temperature of 60 °C featured the highest strength value: 8.90 MPa, and a densified microstructure, compared with the other samples. The contribution of the Na2O in the geopolymerization process was as a self-fluxing agent for the production of the geopolymer ceramic at low temperatures.


2013 ◽  
Vol 662 ◽  
pp. 433-436
Author(s):  
Jiang Zhu ◽  
Guo Zhong Li

Vitrified micro bubbles thermal insulation material was made of vitrified micro bubbles, cement, fly ash, gypsum and sodium silicate, by molding process. VAE emulsion and stearic acid-polyvinyl alcohol emulsion were added to improve water resistance of the material. Mixed with 10% VAE emulsion and 5% stearic acid-polyvinyl alcohol emulsion, properties of the material are followed as: flexural strength 0.64MPa, compressive strength 1.35MPa, softening coefficient 0.71 and 2h volumetric water absorption 6.9%.


2014 ◽  
Vol 1033-1034 ◽  
pp. 1048-1053 ◽  
Author(s):  
Xin Li Zhang ◽  
Hong Hui Zhang ◽  
Yi Qiang Wu ◽  
Yun Chu Hu

In order to improve the water resistance of silicate wood adhesive, a kind of silicate adhesive was prepared from water glass with silica as curing agent, and ammonium stearate as modifier. The chemical structure, surface morphology and thermal properties of the silicate adhesive were characterized by Fourier transform infrared spectrometer, scanning electron microscope, and thermo-gravimetric analyzer. As the two main measures of adhesion properties, the bonding strength and water resistance were also determined. The results showed that ammonium stearate was successfully introduced into the molecule structure of silicate, the silicate adhesive have good thermal stability in the range of 30~800 °C and the modified silicate adhesive had more smooth cured morphology. The bonding strength and 24h water absorption rate of poplar plywood glued by the silicate adhesive was 0.71 MPa and 22.81%, respectively, reaching the grade II of plywood performance's national standard.


2020 ◽  
Author(s):  
Naim Sedira ◽  
João Castro-Gomes

This study determines the effect of ground granulated blast furnace slag (GGBFS) and metakaolin (MK) on the microstructural properties of the tungsten mining waste-based alkali-activated binder (TMWM). During this investigation, TMWM was partially replaced with 10 wt.% GGBFS and 10 wt.% MK to improve the microstructure of the binder. In order to understand the effect of the substitutions on the microstructure, two pastes were produced to make a comparative study between the sample contain 100% TMWM and the ternary precursors. Both precursors were activated using a combination of alkaline activator solutions (sodium silicate and sodium hydroxide) with the ratio of 1:3 (66.6 wt.% sodium silicate combined with 33.33 wt.% of NaOH 8M). The alkali-activated mixes were cured in oven at temperature of 60 °C in the first day and at room temperature for the next 27 days. The reaction products N-A-S-H gel and (N,M)-A-S-H gel resulted from the alkaline activation reaction process. In addition, a formation of natrite (Na2CO3) with needles shape occurred as a reaction product of the fluorescence phenomena. However, a dense matrix resulted from the alkline activation of the ternary precursors containg different gels such as N-A-S-H, C-A-S-H and (N,M)-C-A-S-H gel, these results were obtained through SEM-EDS analyses, as well FTIR tests. Keywords: Mining Waste, Alkali-activated, Microstructure, Slag, Metakaolin


2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Chen-chen Fan ◽  
Qian Tang

This paper aims to develop a modified animal glue sand binder for foundry casting with improved water resistance and bonding strength. An efficient method is reported by using sodium hydroxide as the catalyst to improve the operability of animal glue binder and allyl glycidyl ether as the modifier to improve the water resistance and bonding strength. Sand specimens prepared using allyl glycidyl ether-modified animal glue binder were cured by compressed air at room temperature. The proposed method saves energy and is environmentally friendly and inexpensive. Compared with unmodified animal glue binder, standard dog bone sand specimens with allyl glycidyl ether-modified animal glue binder had higher tensile strength of 2.58 MPa, flowability of 1.95 g, better water resistance (a lower decrease in tensile strength at 25 °C and relative humidity of 60%), and good collapsibility. This allyl glycidyl ether-modified animal glue binder is suitable for practical application in the foundry industry.


Author(s):  
Pratiksha R. Patil

Abstract: Soil stabilization has become the more issue in construction activity. In this study we focus on improvement of soil by using Fly ash and ground granulated blast furnace slag (GGBS). In many villages there was demolition of houses due to flood situation and landslide so stabilization of soil is very important factor in this area. In these studies we use local Fly ash and Ground granulated blast furnace slag (GGBS) for stabilization of soil. Soil are generally stabilized to increase their strength and durability or to prevent soil erosion. The properties of soil vary a great deal at different places or in certain cases even at one place the success of soil stabilization depends on soil testing. Various methods are there to stabilize soil and the method should be verified in the lab with the soil material before applying it on the field. The various percentages of Fly ash and GGBS were mixed with soil sample to conduct soil test. Using fly ash reduces the plasticity index which has potential impact on engineering properties also GGBS has cementations property which acts as binding material for the soil. On addition of 15% Fly ash and 5% GGBS increase the strength of soil (according to IS2720:1985) it’s recommended for better result. Keywords: Stabilization of soil, Fly ash, GGBS, Black cotton soil, Soil test.


Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2561 ◽  
Author(s):  
Liang Jia ◽  
Fangli Zhao ◽  
Jian Guo ◽  
Kai Yao

A certain amount of ferroaluminate cement (FAC) was substituted for MgO during the magnesium phosphate cement (MPC) preparation to obtain the MPC–FAC composite cement. The influence of FAC on the strength, water resistance, pH, and setting time of MPC–FAC composite cement were examined. The microstructure and chemical composition were also analyzed by adopting scanning electron microscopic energy-dispersive spectrometer and X-ray diffraction, respectively. The study showed that setting time of MPC–FAC composite cement was dramatically prolonged when FAC substitution for MgO was between 30 and 40 wt %. The strength of MPC–FAC did not decrease during the early curing time (1 h and 1 d), whereas it increased during the late curing time (3, 7, and 28 days). Moreover, the existence of FAC decreased the hydrated product K-struvite during the early curing time and thus dramatically enhanced the water-resistance of MPC–FAC. With the addition of FAC, a large number of cementitious materials of AFt and AFm, as well as flocculent colloidal substances of AH3, C–S–H, and FH3, were generated during the hydration of MPC, which were filled in the internal pore of the hydrate. Thus, the internal compactness of the sample increased, while the compact protective covering layer was generated on the surface to enhance the water resistance and strength in the late curing time.


2012 ◽  
Vol 626 ◽  
pp. 931-936 ◽  
Author(s):  
Liew Yun Ming ◽  
Kamarudin Hussin ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Mohammed Binhussain ◽  
Luqman Musa ◽  
...  

The properties of metakaolin geopolymer paste are affected by the alkali concentration, the initial raw materials, solidification process, and amount of mixing water as well as the curing conditions. This study aimed to investigate the effect of curing temperature (room temperature, 40°C, 60°C, 80°C and 100°C) and curing time (6h, 12h, 24h, 48h and 72h) on the geopolymer pastes produced from geopolymer powder. The results showed that curing at room temperature was unfeasible. Heat was required for the geopolymerization process, where strength increased as the curing temperature was increased. Moderate elevated curing temperature favored the strength development of geopolymer pastes in comparison with those treated with extreme elevated curing temperature. When geopolymer paste was subjected to extreme elevated curing temperature, shorter curing time should be used to avoid deterioration in strength gain. Similarly, longer curing time was recommended for moderate elevated curing temperature. The microstructure of geopolymer paste cured at moderate curing temperature showed obvious densification of structure. In contrast, the structure formed was weak and less compact at very high elevated curing temperature.


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