Methodology for Proportioning SCC Containing High Powder Content Derived from Crushed Stone Sand

Author(s):  
P. Chandru ◽  
J. Karthikeyan ◽  
P. Parthiban ◽  
C. Natarajan
Keyword(s):  
Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2073
Author(s):  
Qiubai Deng ◽  
Zhenyu Lai ◽  
Rui Xiao ◽  
Jie Wu ◽  
Mengliang Liu ◽  
...  

Waste glass is a bulk solid waste, and its utilization is of great consequence for environmental protection; the application of waste glass to magnesium phosphate cement can also play a prominent role in its recycling. The purpose of this study is to evaluate the effect of glass powder (GP) on the mechanical and working properties of magnesium potassium phosphate cement (MKPC). Moreover, a 40mm × 40mm × 40mm mold was used in this experiment, the workability, setting time, strength, hydration heat release, porosity, and microstructure of the specimens were evaluated. The results indicated that the addition of glass powder prolonged the setting time of MKPC, reduced the workability of the matrix, and effectively lowered the hydration heat of the MKPC. Compared to an M/P ratio (MgO/KH2PO4 mass ratio) of 1:1, the workability of the MKPC with M/P ratios of 2:1 and 3:1 was reduced by 1% and 2.1%, respectively, and the peak hydration temperatures were reduced by 0.5% and 14.6%, respectively. The compressive strength of MKPC increased with an increase in the glass powder content at the M/P ratio of 1:1, and the addition of glass powder reduced the porosity of the matrix, effectively increased the yield of struvite-K, and affected the morphology of the hydration products. With an increase in the M/P ratio, the struvite-K content decreased, many tiny pores were more prevalent on the surface of the matrix, and the bonding integrity between the MKPC was weakened, thereby reducing the compressive strength of the matrix. At less than 40 wt.% glass powder content, the performance of MKPC improved at an M/P ratio of 1:1. In general, the addition of glass powders improved the mechanical properties of MKPC and reduced the heat of hydration.


2021 ◽  
Vol 1904 (1) ◽  
pp. 012012
Author(s):  
Zhe Huang ◽  
Jinyu Xu ◽  
Wei Xia ◽  
Weibo Ren ◽  
Zhihang Wang

2012 ◽  
Vol 204-208 ◽  
pp. 3629-3633 ◽  
Author(s):  
Wei Hou

In order to better master the production process and the road performance of rubber asphalt, the paper studied the influence law of mixing method, mixing temperature, mixing time and rubber powder content on the performance of rubber asphalt. The results show that all the indexes except the viscosity of rubber asphalt has little change with different mixing methods, and the rubber asphalt has the best performance under the high-speed stirring molding method but the worst performance under the high-speed shearing molding method. Meanwhile, the performance of rubber asphalt change visibly with different mixing temperatures, on which the excessively high or low production temperature has negative significance, so the optimal production temperature would be recommended as 180~200°C. Furthermore, the mixing time and the rubber powder content are the two critical factors which may greatly affect the performance of rubber asphalt, followed by the mixing temperature and the mixing method.


2021 ◽  
Vol 1021 ◽  
pp. 21-34
Author(s):  
Zahraa Alaa M.A. Ali Khan ◽  
Zena K. Abbas

Roller compacted concrete (RCC) is a special type of concrete with zero or even negative slump consistency. In this work, it had aimed to produce an RCC mix suitable for roads paving with minimum cost and better engineering properties so, different RCC mixes had prepared i.e. (M1, M2, M3, and M4) using specified percentages of micro natural silica sand powder (SSP) as partial replacement of (0%, 5%, 10%, and 20%) by weight of sulfate resistant Portland cement. Additionally, M-sand, crushed stone, filler, and water had been used. The results had obtained after 28 days of water curing. The control mix (M1) had satisfied the required f ‘c with accepted results for the other tests. M2 mix with SSP of 5% had achieved the highest results. The f ’c for sawed cubes of (10*10*10) cm had increased by 2.26% and 3.16% when tested in directions (ꓕ and //) to the direction of loading respectively. R results for sawed prisms of (38*10*10) cm had increased by 8.78% and 8.43% when tested on top and bottom faces respectively. The density had increased by 1.04% while the absorption and volume of permeable voids had decreased by 8.11% and 7.83% respectively. The UPV results had also increased by 2.44% and 0.81% for cubes and prisms respectively when compared to the control mix. M3 mix with SSP of 10% had also achieved satisfactory results when compared to the control mix.


2021 ◽  
Vol 11 (5) ◽  
pp. 724-731
Author(s):  
Hemin Liu ◽  
Qian Huang ◽  
Liang Zhao

This study investigates the deterioration of concrete containing limestone powder exposed to sulfate solution under ambient temperature (20~25 °C). Microstructure and mineral phases within the attacked concrete were measured by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). It was found that the addition of limestone powder increased the initial porosity of concrete. Consequently, a larger amount of SO2–4 ions diffused into the concrete containing limestone powder, and their degree of deterioration caused by sulfate attack increased with the increase in limestone powder content. At ambient temperature, gypsum and ettringite were the major attack products, respectively within the surface and nearsurface portions of concrete containing limestone powder, which was consistent with the products of sulfate attack within concrete without limestone powder. Therefore, the type and distribution of the attack products in concrete had not been revised due to the addition of limestone powder. Nevertheless, the adverse influence of limestone powder on the sulfate resistance of concrete, even at ambient temperature, should be considered. Furthermore, effective measures should be implemented to improve the durability of concrete containing limestone powder in this environment.


2021 ◽  
Vol 2021 (24) ◽  
pp. 48-59
Author(s):  
Anatolii Mudrychenko ◽  
◽  
Ivan Balashov ◽  
Sergey Illyasch ◽  
◽  
...  

ntroduction. Rehabilitation of public roads network requires a comprehensive recovery with strengthening of the bearing capacity of the pavement foundation. Rehabilitation of the foundation bearing capacity performed by arranging layers of road material made by cold recycling technology (hereinafter — CRRM) in accordance with [4] or by arranging a layer of crushed stone — sand mixture reinforced with cement or complex binder (hereinafter — CSSM 20) according to [13]. Purpose. The purpose of the work is to study the feasibility of using acrylic additives for the preparation of mixtures made by cold recycling technology and crushed stone-sand mixtures treated with cement in the layers of pavement foundation. Materials and methods. Experimental comparative tests of CRRM and CSSM 20 with different content of complex binder were performed. Results. Feasibility of acrylic additives use has been established (hereinafter — the additive) for the preparation of CRRM and CSSM 20 in the pavement foundation layers. Recommendations on technological parameters of preparation, transportation, laying and compaction of mentioned mixtures are given. Conclusions. Performed researches have shown that according to physical and mechanical indicators CRRM and CSSM20 meet the requirements of the current normative documents of Ukraine. The advantages of use are noted.


Author(s):  
Yan-Xian Sun ◽  
Hong-Min Guan ◽  
Zhao-Hua Jiang ◽  
Zhen-Bo Wang

The prelithiation of hard carbon electrode using stable metal lithium powder to compensate the lithium loss during the first lithium insertion is studied in this work. The results show that when the pressure on lithium powder surface is 6 MPa, the Li2CO3 protective layer on the surface of stable metal lithium powder is completely squeezed, which is conducive due to the full contact between the metal lithium and the hard carbon. The prelithiation of hard carbon has little effect on the initial charge capacity and cycle life. Both the pre-lithium capacity and the utilization efficiency of lithium powder increase with the increasing of the lithium powder content, and when the amount of lithium powder is 3 g m−2, the utilization efficiency of lithium powder is 56%.


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