Properties of reactive powder concrete incorporating silica fume and rice husk ash

2018 ◽  
Vol 9 (4) ◽  
pp. 114 ◽  
Author(s):  
Mohamed Amin

Reactive Powder Concrete (RPC) is composed of very fine powders (cement, sand, and pozzolanic materials), and superplasticizers. A very dense matrix is found, and this tightness provides RPC with ultra-high strength and durability. Recently, using supplementary cementing materials associates greatly with ultra-high strength and the mix design of ultra-high performance concrete (UHPC). These materials could be natural, by-products or industrial wastes. They could be also less energy consuming and little time produced materials. Silica fume (SF), rice husk ash (RHA) and granulated blast furnace slag (GBFS) etc. are among the major supplementary cementing materials utilized. The detailed experimental investigation done to study the impact of partial alteration of cement with SF, RHA, and GBFS on concrete properties. This study aims to a minor replacement of Portland cement by SF, RHA and GBFS to reach UHPC. Twenty-five different concrete mixes (fc =150.1 to 188.2 MPa) with and without SF, RHA and GBFS were prepared with local materials in Egypt. Concrete mixes were cast with 0, 10, 15, 20, and 25% cement replaced by either SF or RHA, and another proportions taken combination between SF and RHA or SF and GBFS or RHA and GBFS about percentages from 10 to 15%. The mixes were tested for slump flow, air content, mechanical properties and water permeability. The findings of hardened properties indicate that optimum level for partial changing of cement by SF and RHA was 20% and it is observed that though the strengths of SF or RHA concrete goes on decreasing after the 20% addition of SF or RHA. Test results have indicated that RHA exhibits lower pozzolanic activity than SF.

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.


2012 ◽  
Vol 174-177 ◽  
pp. 1090-1095 ◽  
Author(s):  
Kai Pei Tian ◽  
Yang Ju ◽  
Hong Bin Liu ◽  
Jin Hui Liu ◽  
Li Wang ◽  
...  

The explosive spalling of high-strength concrete due to fire is a problem that has garnered increasingly widespread attention, particularly the explosive spalling of reactive powder concrete (RPC). For years, based on the vapor pressure mechanism, the addition of fibers has been demonstrated to be somewhat effective in protecting against spalling. However, relevant experiments indicate that fibers are not effective for dense concrete, which is a challenge for the simple vapor pressure mechanism in providing spalling resistance for RPC. The authors found that silica fume plays an important role in the explosive spalling of RPC. Thus, four classes of RPCs with different ratios of silica fume were prepared, and the spalling phenomena and the inner temperature distribution during heating were investigated. The results show that silica fume content has a prominent effect on the spalling process of RPC.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Anthony Torres ◽  
Federico Aguayo ◽  
Srinivas Allena ◽  
Michael Ellis

A superplasticizer is a type of chemical admixture used to alter the workability (viscosity) of fresh concrete. The workability of fresh concrete is often of particular importance when the water-to-cement (w/c) ratio is low and a particular workability is desired. Reactive Powder Concrete (RPC) is a high-strength concrete formulated to provide compressive strengths exceeding 130MPa and made of primarily powders. RPC materials typically have a very low w/c, which requires the use of a chemical admixture in order to make the material workable for placing, handling and consolidating. Superplasticizer are commonly used for this purpose. Superplasticizers are developed from different formulations, the most common being Polynaphthalene Sulfonate (PNS), Polymelamine Sulfonate (PMS) and Polycarboxylate Ether (PCE). This study investigates the impact of various PNS based superplasticizers on the compressive strength and rheological performance of a RPC mixture. Six different types of PNS based superplasticizers were used; three of various compositional strengths (high, medium, low range) from a local provider, and three of the same compositional strengths (high, medium, low) from a leading manufacturer. Specific properties assessed were the superplasticizers viscosity, concrete workability through the mortar-spread test, concrete rheology, and 7, 14, and 28 day RPC compressive strengths. Two mixtures were produced with two w/cm (0.20 and 0.15), which would subsequently increase the amount of superplasticizer needed, from 34.7L/m3 to 44.5L/m3. The results show that the name brand high range composition produced the overall highest spread, lowest viscosity, and a highest compressive strength at all ages tested. However, the local provider outperformed the name brand in the mid and low range compositions. Additionally, the rheology test also demonstrated that the name brand high range, and RPC produced with the name brand high range, had a lower viscosity at all angular speeds than the others tested.


2019 ◽  
Vol 4 (6) ◽  
pp. 74-83 ◽  
Author(s):  
Gamal I. K. ◽  
K. M. Elsayed ◽  
Mohamed Hussein Makhlouf ◽  
M. Alaa

Reactive Powder Concrete RPC is comprise of (cement, quartz powder, sand, and superplasticizer) mixture with low water/cement ratio. It has not coarse aggregates and characterized by highly dense matrix, high strength concrete, excellent durability, and economic. This study aims to investigate fresh and hardened properties of locally cast RPC with several available economical materials such as silica fume (SF), fly ash (FA), steel fiber (STF), and glass fiber (GF). Experimental investigation were performed to study the effectiveness of partial replacement of cement by SF or FA to reach ultra-high strength concrete, effect of additional materials STF or GF in order to improve the fracture properties of the RPC mixes, and influence of the treated with normal water as well as with hot water. Fifteen different RPC mixes were cast with 20, 25, 30, and 35% cement replacement by SF, 25% cement replacement by FA, and another proportions taken combination between SF and FA with percentages 15, 20, 25% FA and constant 10% SF. Varying fiber types (steel fiber or glass fiber) added to concrete by different percentages 1, 2, and 3%. Specimens were treated with normal water 25ᵒC and hot water at 60ᵒC and 90ᵒC by 2 mixes with silica fume content 25% of binder and steel fiber content 2% by total volume. Performance of the various mixes is tested by the slump flow, compressive strength, flexure strength, splitting tensile strength, and density. The production of RPC using local materials is successfully get compressive strength of 121 MPa at the age of 28 days at standard conditions and normal water curing 25°C with Silica fume content 25% of binder and steel fiber content 2% by total volume of RPC and water/binder ratio of 0.25.  The results also showed the effect of curing by hot water 60 and 90°C, it is observed that compressive strength increases proportionally with curing temperatures and a compressive strength of 149.1 MPa at 90°C for 1days was obtained.


2021 ◽  
Vol 233 ◽  
pp. 01053
Author(s):  
Yang Ming ◽  
Pengliang Sun ◽  
Ping Chen ◽  
Yuanhao Wang ◽  
Ling Li ◽  
...  

The effect of grinding time on the properties of low-temperature rice husk ash was experimentally studied, and the feasibility of using rice husk ash instead of silica fume to prepare concrete was studied by comparison with silica fume. The results showed that the best grinding time of rice husk ash is 50 minutes, the concrete with similar properties can be prepared by replacing silica fume with super-fine rice husk ash, and the same enhancement effect can be achieved when replacing silica fume with more than 5%, and the performance was consistent.


2018 ◽  
Vol 7 (2.24) ◽  
pp. 552
Author(s):  
Jeganmurugan P ◽  
Rakesh Senthil Kumar G V ◽  
Sivasharmina M ◽  
Sowmiya S ◽  
Vasanthan M

Reactive powder concrete (RPC) is ultra high strength with advanced mechanical properties. Reactive powder concrete is a concrete without coarse aggregate, contains cement, silica fume, quartz sand, quartz powder, super plasticizer, steel fibre and polypropylene fibre with very low water cement ratio under normal curing condition. RPC has been produce with high compressive strength ranging from upto 800 MPa with high flexural strength up to 50 MPa and in some cases provided with absences of steel reinforcement. Mix proportions of RPC were found by trial and error method, the concrete cubes of size 100mmx100mmx100mm were cast for find compressive strength of NRPC at 7days. Concrete cubes and cylinders of sizes 100mmx100mmx100mm and 100mmx150mm have to be cast for finding compressive strength and split tensile strength at 28 days. Flexural strength of NRPC and MRPC will be find out by casting prism of size 500mmx 100mmx 100 mm. The optimum mix proportion has to be finalized by comparing the results of all concrete specimens. Compressive strength test results shows that addition of silica fume upto 0.22% will increase the compressive strength of reactive powder concrete.   


2018 ◽  
Vol 8 (12) ◽  
pp. 2507 ◽  
Author(s):  
Umut Bektimirova ◽  
Chang-Seon Shon ◽  
Dichuan Zhang ◽  
Eldar Sharafutdinov ◽  
Jong Kim

Reactive Powder Concrete (RPC) is a newly emerging concrete material that is being used for various applications where high-strength concrete is required. RPC is obtained by removing coarse aggregates and adding fine powders such as silica fume into the concrete mixture. This research has focused on the proportioning and characterization of RPC mixture to be used as a material for energy storage pile application. For mixture parameters, the water-to-binder ratio (WB), silica fume (SF) content, and normal and warm temperature curing have been selected. The relative flowability, penetration resistance, setting time, drying shrinkage, and compressive and flexural strengths were evaluated. Based on the test results, the mixture with WB = 0.22 and SF = 20% was the best mixture with the highest tensile strength and other characteristics. Response surface methodology (RSM) was used to design the experiments and find the optimum mixture proportions to achieve the highest compressive strength. The optimum WB and SF content to achieve the highest strength for combined ages (7 days, 28 days, and 56 days) was determined to be WB = 0.213 and SF = 20%. Through the comparison between the test results and the required strength from analytical simulations, the RPC studied in this paper was deemed to be suitable for the energy storage pile.


Teras Jurnal ◽  
2017 ◽  
Vol 3 (2) ◽  
pp. 157
Author(s):  
Yulius Rief Alkhaly

<p>Reactive powder concrete (RPC) merupakan varian baru dari beton mutu ultra tingggi (ultra high strength concrete) yang diperkenalkan kepada umum pertama kali pada tahun 1994. Beton modern ini memiliki beberapa keunggulan dibandingkan beton konvensional (normal concrete) atau beton kinerja tinggi (high performance concretes). Penelitian tentang RPC di Indonesi masih sangat terbatas, RPC pertama bermaterial lokal Indonesia dikembangkan tahun 2009, dengan sumber silika berasal dari silica fume. Sebagai bagian dari berbagai penelitian lanjutan tentang RPC, hasil akhir dari riset ini diharapkan dapat menghasilkan RPC yang benar-benar sesuai dengan karakteristik material di Indonesia. Sumber silika yang digunakan berasal dari limbah bahan organik sehingga dapat menekan biaya produksi dan menghasilan green concrete yang dapat mengurangi dampak negatif limbah terhadap lingkungan.</p><p><strong>Kata kunci:</strong> Reactive Powder Concrete, Silika, Limbah Bahan Organik</p>


2021 ◽  
Vol 892 ◽  
pp. 43-50
Author(s):  
Yulius Rief Alkhaly ◽  
Abdullah ◽  
Husaini ◽  
Muttaqin Hasan

Original reactive powder concrete (RPC) consists of a large amount of cement, fine sand, crushed quartz, and silica fume, with a very dense matrix achieved by optimizing the granular packaging of the materials. This study, therefore, applied the modified Andreasen & Andersen particle-packing model using Aceh quartzite powder to design a densely compacted matrix and low cement content RPC mixtures. The research involved the preparation of two series of the mixture with different percentages of silica fume and Aceh quartzite powder and the 70.7 mm cube specimens were treated with combined steam curing and normal curing after which their compressive strength was tested at the age of 7 days and 28 days. The result showed the use of 61% local quartzite powder by weight of cement through an optimized mix design and cured treatment improves the RPC strength at any variation of silica fume.


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