Effect of Heat-Curing Procedure on Strength and Microstructure of Reactive Powder Concrete Having High Volume of Mineral Admixtures

2012 ◽  
Vol 204-208 ◽  
pp. 3989-3993
Author(s):  
Yan Zhou Peng ◽  
Wen Yang ◽  
Qiao Sheng Zhu
Keyword(s):  
Steel Slag ◽  
Great Influence ◽  
High Volume ◽  
Pozzolanic Reaction ◽  
Curing Temperature ◽  
Mineral Admixtures ◽  
Reactive Powder Concrete ◽  
Heat Curing ◽  
Reactive Powder ◽  
Curing Procedure

The effect of heat-curing procedure on strength of reactive powder concrete (RPC) having high volume of mineral admixtures, such as ultra-fine fly ash (UFFA), steel slag powder (SS) and silica fume (SF) was studied in this paper. Moreover, the effect of the cuing temperature (20°C, 60°C and 90°C) and the duration (1 day and 3 days) of heat-curing both on microstructure of RPCs’ samples were investigated by SEM-EDXA. The results indicate that the heat-curing procedure has a great influence on strength of this RPC; the compressive strength of specimens cured in a appropriate condition could achieve more than 190 MPa. Moreover, a high curing temperature or a long duration of heat-curing will cause not only a high degree of pozzolanic reaction but also a low n(Ca)/n(Si) ratio of hydration product. Thus, the microstructure of the paste becomes more compact, which would definitely improve the mechanic properties of the hardened paste.

Investigation of hydration and pozzolanic reaction in Reactive Powder Concrete (RPC) using 29Si NMR

1996 ◽  
Vol 26 (1) ◽  
pp. 93-100 ◽  
Author(s):  
Hélène Zanni ◽  
Marcel Cheyrezy ◽  
Vincent Maret ◽  
Samuel Philippot ◽  
Pedro Nieto
Keyword(s):  
Pozzolanic Reaction ◽  
Reactive Powder Concrete ◽  
29Si Nmr ◽  
Reactive Powder

Effects of Curing Systems on the Strength and Microstructure of Reactive Powder Concrete with Iron Tailing Sands

2014 ◽  
Vol 548-549 ◽  
pp. 247-253
Author(s):  
Zhi Gang Zhu ◽  
Bei Xing Li ◽  
Jin Cheng Liu ◽  
Xing Dong Lv
Keyword(s):  
Point Of View ◽  
Hot Water ◽  
Curing Temperature ◽  
Reactive Powder Concrete ◽  
Curing Time ◽  
Submicroscopic Structure ◽  
Curing Conditions ◽  
The Difference ◽  
Reactive Powder ◽  
Curing Systems

To produce 130MPa reactive powder concrete with iron tailing sands as aggregation in an economic hot curing system, the effects of curing temperature, curing time and curing conditions on the reactive powder concrete was studied, the reasons of the strength of reactive powder concrete in different curing systems has the difference from the submicroscopic structure point of view was analyzed. The results show that use 90°C hot water to cure reactive powder concrete for 48h can lead it’s 28 day compressive strength reaches 140MPa, the flexural strength reaches 28MPa.

Mix Proportion Optimization and Shrinking of New Developed Reactive Powder Concrete

2009 ◽  
Vol 405-406 ◽  
pp. 37-43 ◽  
Author(s):  
Heng Jing Ba ◽  
Ai Li Guo ◽  
Ying Zi Yan
Keyword(s):  
Raw Materials ◽  
Steel Fibers ◽  
Reactive Powder Concrete ◽  
Particle Sizes ◽  
Heat Curing ◽  
Mix Proportion ◽  
Binder Ratio ◽  
New Type ◽  
Dry Shrinkage ◽  
Reactive Powder

According to the theory of dense packing of particle, the theoretical particle size distribution of raw materials of RPC (Reactive Powder Concrete) was calculated. On the basis, the ratio of raw materials with different range of particle sizes of the RPC was determined by mechanical experiments. According to the determined ratio, a new type RPC was prepared by using flying ash and slag to replace part of cements and quartz flour, respectively. The workability, mechanical properties of the new RPC with different mix proportion and its shrinkage, cured at the normal temperature and 60°C, respectively, were studied. The results show that when water-binder ratio is 0.23, fly ash replaces 30% cements, slag replaces 50% quartz flour and superfine steel fibers percentage in volume is 2%, the compressive and flexural strength of prepared RPC are 160.1MPa and 25.3MPa, respectively, and after 3days heat curing (60°C), the dry shrinkage of it in 28days age reaches 299um/m. In addition, the fluidity of the new RPC is 258mm and meets requirements of workability of the pump concrete.

scholarly journals Utilization of Rice Husk Ash in Reactive Powder Concrete

2019 ◽  
Vol 8 (4S2) ◽  
pp. 82-86
Keyword(s):  
Compressive Strength ◽  
Silica Fume ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Curing Temperature ◽  
Partial Replacement ◽  
High Price ◽  
Reactive Powder Concrete ◽  
Durability Properties ◽  
Reactive Powder

Reactive Powder Concrete (RPC) is a special concrete with excellent mechanical and durability properties and it is differentiated with other forms of concrete in terms of production, mix proportion etc. Depending upon various parameters like composition and the curing temperature, its compressive strength ranges from 130 MPa to 750 MPa, bending strength varies as 29 to 51 MPa and Young's modulus results upto 50GPa to 75GPa.Though RPC possesses many outstanding properties, it has limited applications in the construction field. The usage of higher quantity of cement and Silica Fume causes the rise of production of RPC. In addition to that, the silica fume availability is also restricted. For a country like India, usage of SF is limited due to its high price. Also, mineral admixtures can be used as a suitable alternative. Hence in this research work, Rice Husk Ash (RHA) is used as a possible alternatives for replacing silica fume in RPC. RHA holds maximum amount of silica (approx. 96%) in amorphous form. In this research, an experimental research on mechanical and durability properties of RPC by partially replacing SF with RHA. The detailed literature survey on constituent materials, mix proportions and curing conditions of RPC were done. Also, the optimum temperature and duration for the thermal treatment of RHA were identified. The compressive strength of the specimens of partial replacement of Silica Fume using RHA were tested and the results were compared with control specimens compressive strength.

Hydration and microstructure of concrete containing high volume lithium slag

2020 ◽  
Vol 10 (3) ◽  
pp. 430-436
Author(s):  
Zhihai He ◽  
Jingyu Chang ◽  
Shigui Du ◽  
Chaofeng Liang ◽  
Baoju Liu
Keyword(s):  
Mercury Intrusion Porosimetry ◽  
High Volume ◽  
Cementitious Materials ◽  
Pozzolanic Reaction ◽  
Supplementary Cementitious Materials ◽  
Mineral Admixtures ◽  
Sustainable Construction ◽  
Mercury Intrusion ◽  
Variation Trends ◽  
Lithium Slag

Due to requirements for environmental protection, saving of resources and sustainable construction in the future, investigation on the use of high volume mineral admixtures as supplementary cementitious materials in concrete was carried out in this study. The effect of high volume lithium slag (LS) to partially replace cement by weight on compressive strengths of concrete was experimentally investigated, and the hydration of hardened paste was measured by non-evaporable water. Moreover, the microstructure of concrete was determined by mercury intrusion porosimetry and scanning electron microscope methods. Results showed that the use of high volume LS reduced compressive strengths of concrete at early ages, and compressive strengths were remarkably improved at later ages, with concrete containing 40% LS being close to that of the control concrete. Hydration of hardened paste showed similar variation trends with compressive strengths. The highvolume LS degraded concrete microstructure at early ages, and 40% LS improved concrete microstructure at the later ages, due to the filling effect and pozzolanic reaction of LS. However, there still existed defects in microstructure of concrete containing 60% LS, with increased harmful porosity, especially interfacial transition zone.

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