Study of the Microstructure of Industrial Residues and its Application in High Performance Concrete

2013 ◽  
Vol 800 ◽  
pp. 117-122 ◽  
Author(s):  
Li Bin Xu ◽  
Nai Qian Feng ◽  
Kia Hui Tew

Along with the rapid development of China and its eye-catching economic take-off, industrial production has brought about increasingly enormous negative impact. Industrial residues (coal ash, iron-ore slag, phosphorous slag and ganister sand) have accumulated in large quantities, thus severely contaminating the environment and greatly restricting the sustainable economic development. This paper conducts research on microstructure of the industrial wastes that are massively applied in domestic architectural material industry, such as coal ash, (S95S105) slag powder, S75 phosphorous slag, micro-bead (ultra-fine coal ash) and the micro ganister sand so as to analyze its size distribution and particle appearance and introduce its functions and effect in concrete and other cement products.

2013 ◽  
Vol 357-360 ◽  
pp. 588-591 ◽  
Author(s):  
Yan Zhou Peng ◽  
Jin Huang ◽  
Jin Ke

Reactive powder concrete (RPC) is an ultra-high performance concrete (UHPC). Cement and silica fume content of RPC are generally rather high compared to the conventional concrete. The aim of this paper is to decrease the cement content of RPC by using phosphorous slag powder. Firstly the effect of grinding time on the activity index of phosphorous slag was investigated. And then, the mix proportion design of this UHPC containing phosphorous slag powder and silica fume was done through orthogonal design. The results indicate that the utilization of phosphorous slag powder in RPC is feasible when the dosage of phosphorous slag powder is about 35% (by weight of the binder) and the water-binder ratio is less than 0.18. By substituting phosphorous slag powder for a part of cement and keeping the water-binder ratio at about 0.14, UHPC specimens whose content of mineral admixtures, including phosphorous slag powder and silica fume, was about 40%~50% (by weight of the binder) were obtained after they had been cured in 80 °C water for 72 hours. The compressive and flexural strength of those specimens was more than 150 MPa and 20 MPa respectively.


Author(s):  
Keli Xiao ◽  
Yanjun Jin ◽  
Aijia Zou ◽  
Lin Li ◽  
Wei He

<p>The bicycle viaduct is an effective method to solve the contradiction between the rapid development of urbanization and low carbon. In this paper, a 4.8km long viaduct was designed between the Happy Valley and Phoenix Peak park of Chengdu, China. The standard sections of the whole viaduct adopt steel box girder and Ultra High Performance Concrete (UHPC) precast beam with 30m spans and 5.5m widths of bridge deck (single). And the UHPC connection plate is used to replace the traditional mechanical telescopic device to realize the continuous bridge deck between the ends of the simple beam, which embodies the concept of ‘green bridge’. This line focuses on the design of three nodes, which includes the five towers cable-stayed bridge, the double deck arch bridge across the Fu River and the continuous beam bridge in leisure area. The three bridges enrich the bridge modelling, reflecting the application of aesthetics in the bridge. The whole traffic is based on bicycle, which adopts separation traffic with double speed of fast and slow speed and can be used for sightseeing and travel. This design highlights the people-oriented, can ensure traffic safety and achieve a ‘safe travel, green travel’. Therefore, the viaduct is an effective means to solve the disharmony between the urban development and the environment.</p>


2011 ◽  
Vol 194-196 ◽  
pp. 956-960 ◽  
Author(s):  
Yan Zhou Peng ◽  
Kai Chen ◽  
Shu Guang Hu

The interfacial properties of reactive powder concretes (RPCs), other known as ultra-high performance concrete (UHPC), containing steel slag powder and ultra fine fly ash are studied in this paper. The microstrctural characterization of interfacial transition zones (ITZs), including the aggregate-cement paste interfacial zone and the steel fiber-paste interfacial zone, is investigated by SEM. The microhardness of the aggregate-paste ITZ and the steel slag-paste ITZ is studied and the bond strength of steel fiber in matrix is tested through fiber pullout tests. The results indicate that the microhardness of the steel slag-paste ITZ is slightly higher than that of the aggregate-paste ITZ, which implies the advantage of the substitution of quartz powder with steel slag powder in preparation of RPCs to some degrees. Moreover, the hardness of these two ITZs is higher than that of the hardened paste. A certain amount of hydration products has been observed exsiting on the surface of steel fiber by SEM and the bond strength of steel fiber-martix is up to 9.3MPa. These interfical properties are definitely critical to obtain high performance of UHPCs containing steel slag powder and fly ash.


2013 ◽  
Vol 671-674 ◽  
pp. 1839-1843
Author(s):  
Yuan Gang Wang ◽  
Chao Wan ◽  
Kai Jian Huang ◽  
Gao Qin Zhang ◽  
Ya Feng Hu

Several compound mineral admixtures, such as steel slag powder, granulated blast furnace slag powder and silica fume, are mixed with proper proportion to improve the workability of High Performance Concrete(HPC). Through the orthogonal experiment, workability of HPC is analyzed on water-binder ratio, sand ratio, the amount of superplasticizer and the amount of compound mineral admixtures. Results show that: workability of HPC was significantly effected by the amount of naphthalene sulphonate water-reducing admixture and water-binder ratio, the amount of compound mineral admixtures and sand ratio are impact factors on the workability in a certain extent.


2021 ◽  
Vol 879 ◽  
pp. 34-48 ◽  
Author(s):  
Chong Beng Wei ◽  
Rokiah Othman ◽  
Ramadhansyah Putra Jaya ◽  
Shu Ing Doh ◽  
Xiao Feng Li ◽  
...  

Solid waste management is one the leading problems in Malaysia. Rapid development and population growth have prompted researches to improve the recycling and reusing of waste material for sustainable development. Chicken eggshell is discarded in Malaysia as municipal waste, while waste tyre is a waste that is difficult to handle and often ends up in the landfill. This paper presents the properties of high performance concrete with eggshell powder and tyre rubber crumb as partial replacement of cement and sand. Grade 45 concrete was prepared with 5% tyre rubber crumb as sand replacement and up to 15% of eggshell powder as cement replacement. The mechanical strength of concrete was investigated for up to 90 days while durability properties were studied through water absorption and carbonation test. Results show that concrete with 5% eggshell powder is optimal for high mechanical properties, lower water absorption and low carbonation depth. X-Ray Diffraction of concrete shows increase of calcite compound which contributes to the gain of strength. Microstructure analysis with SEM and EDX provides insight of the improved performance, which is attributed to a denser C-H-S gels and finer pore structure.


2019 ◽  
Vol 240 ◽  
pp. 118157 ◽  
Author(s):  
Rui Yang ◽  
Rui Yu ◽  
Zhonghe Shui ◽  
Xu Gao ◽  
Xunguang Xiao ◽  
...  

2019 ◽  
Vol 4 (2) ◽  
pp. 77 ◽  
Author(s):  
Bunga Yubi Nabiilah ◽  
Lisa Oksri Nelfia ◽  
Sotya Astutiningsih

ABSTRACT Nickel slag is a solid waste produced from the nickel smelting process. At present, In Indonesia, the total capacity of domestic nickel smelting reaches 5 million tons/year with the assumption of NPI or FeNi production with a Ni level of 10%, requiring the input of Ni ore raw materials around 40 million tons/year in which around 30 million tons will become waste/slag. Currently, the area of Southeast Sulawesi has a potential of huge nickel resources of 97.4 billion tons, which spread over 480 thousand hectares of land. This has led to a continuous increase in the demand of concrete towards infrastructural development in Indonesia. Therefore, the aim of this research is to reuse nickel slag powder in the context of environmentaly friendly by analyzing the tensile strength using nickel slag powder (NSP) as a cement substitution material for the manufacture of high-performance concrete. Specimens were made with water-cement ratio of 0.31 and compared with 100% OPC Type 1 cement (as reference). Furthermore, the NSP substitution of cement were 5%, 10%, 15%, 20%, 25% and 30% with a concrete age of 3, 7, 14 and 28 days. Analysis of physical characteristics of nickel slag powder and cement were carried out by using the Le Chatelier method, while the mechanical characteristics comprised ease of work in the field (workability) and split tensile strength. The manufactured concrete was made by using Sika Viscocrete 8015 superplasticizer admixture with split tensile strength test results for NSP substitution at 28 days ≥ 5% of the value of compressive strength. Keywords: High-performance concrete, Nickel slag powder, Split tensile strength,


2009 ◽  
Vol 79-82 ◽  
pp. 175-178 ◽  
Author(s):  
Yun Feng Li ◽  
Yang Liu ◽  
Rong Qiang Du ◽  
Fan Ying Kong

dvanced mineral admixtures can lead to economical high performance concrete with enhanced durability and reduced cement content. When super fine steel slag powder is mixed into concrete as active admixture, resistance to abrasion and resistance to chloride penetration are improved as well as workability and mechanical properties of the concrete. Resistance to abrasion of steel slag concrete is measured and resistance to chloride penetration is also determined by the method of NEL and ASTM C1202 in this paper. Result shows that compound mineral admixtures as partial replacement for Portland cement in mortar enhance abrasion resistance. Mixing mineral admixture is an effective means for controlling the chloride permeability. Concrete specimens prepared with compound mineral admixture with steel slag powder and blast furnace slag powder has very low permeability.


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