scholarly journals Use of Thermostone Waste Aggregates for Internal Curing of Reactive Powder Concrete

2021 ◽  
Vol 877 (1) ◽  
pp. 012043
Author(s):  
Mena A. Gawad ◽  
Nada M. Fawzi
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Strength ◽  
Concrete Surface ◽  
Internal Curing ◽  
Modulus Of Rupture ◽  
Partial Replacement ◽  
Reactive Powder Concrete ◽  
Curing Methods ◽  
Reactive Powder

Abstract The concrete need curing for cement hydration that is a chemical reaction in each step require water supply throughout the time period. The traditional concrete cured by external method that prevents the concrete surface dry so that keeping the concrete mixture wet and warm. The internal curing was adopted in normal and high strength concrete such as reactive powder concrete. In present paper, experimental approach is to study the mechanical properties of reactive powder concrete cured internally with thermostone material. The materials that adopted to evaluate and find out the influences of the internal curing on the mechanical properties of reactive powder concrete is focused with different curing methods such as in water, air and combined water and air. Thermostone aggregate are used as partial sand replacement by volume with different percentages to explore the percentage that effects of the concrete mechanical properties. Test results showed that the best partial replacement by thermostone is 5% gave enhancement and increase in compressive strength and flexural resistance strength (modulus of rupture) and concrete density. Highest increasing of compressive strength is 10.07in case of 5% partial replacement at 90 days. In case of cured the specimens up to 90 days, the increase in modulus of rupture is 4.53%

Tests on Mechanical Properties and Anti-Explosion Performance of Steel-Fiber Reactive Powder Concrete

2011 ◽  
Vol 368-373 ◽  
pp. 436-440
Author(s):  
Chun Ming Song ◽  
Ming Yang Wang ◽  
De Rong Wang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Compressive Strength ◽  
Shear Strength ◽  
Steel Fiber ◽  
High Strength ◽  
Reactive Powder Concrete ◽  
Compression Coefficient ◽  
Reactive Powder ◽  
Very High

In order to get mechanical properties and anti-explosion capability parameters, some RPC samples with 5% steel fiber are tested, many groups data were obtained such as compressive strength, shear strength and fracture toughness. The model tests are also carried out on RPC shelter plate under contact explosion, the most important parameter to express anti-explosion capability,i.e. compression coefficient of the material, is obtained by above experiments and theory study, the results of tests show RPC with steel fiber has very high strength and anti-explosion capability, its compressive strength and anti-explosion capability are about six and three times higher than those of C30 concrete respectively.

Tests on Mechanical Properties and Anti-Penetration Performance of Steel-Fiber Reactive Powder Concrete

2013 ◽  
Vol 671-674 ◽  
pp. 1761-1765
Author(s):  
Yong Liu ◽  
Chun Ming Song ◽  
Song Lin Yue
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Steel Fiber ◽  
Reactive Powder Concrete ◽  
Calculation Results ◽  
Reactive Powder ◽  
Penetration Tests

In order to get mechanical properties ,some RPC samples with 5% steel fiber are tested, many groups data were obtained such as compressive strength, shear strength and fracture toughness. And a group of tests on RPC with 5% steel-fiber under penetration were also conducted to validate the performance to impact. The penetration tests are carried out by the semi-AP projectiles with the diameter of 57 mm and earth penetrators with the diameter of 80 mm, and velocities of the two kinds of projectiles are 300～600 m/s and 800～900 m/s, respectively. By contrast between the experimental data and the calculation results of C30 reinforced concrete by using experiential formula under penetration, it shows that the resistance of steel-fiber RPC to penetration is 3 times as that of general C30 reinforced concrete.

scholarly journals A Study on Optimum Mixture Ratio of Reactive Powder Concrete

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Mingyang Chen ◽  
Wenzhong Zheng
Keyword(s):  
Compressive Strength ◽  
Steel Fiber ◽  
Raw Materials ◽  
Reactive Powder Concrete ◽  
Mixture Ratio ◽  
Curing Methods ◽  
Main Components ◽  
Cement Strength ◽  
Reactive Powder ◽  
Design Factors

To optimize the main components of reactive powder concrete (RPC) for various curing methods, based on the fluidity and compressive strength, an inclusive experimental research is conducted on 58 different mixture ratios. The results indicate that owing to the increase of the cement strength, the RPC fluidity decreases and the cement strength is not proportional to the compressive strength. The addition of the fly ash and the nano-microbead is an effective way to improve the fluidity, and it is required at the low W/B ratio. However, the influence of the SF grade on the strength and fluidity is almost negligible. By considering the fluidity, strength, and economy of RPC as crucial design factors, SF90 is suggested. The contribution of the steel fiber to the compressive strength cannot be ignored. The upper envelope value of the steel fibers is required for the structure to resist appropriately against the fire. According to the test results, the mixture ratio formula is proposed through considering the characters of different compositions and curing methods. The strength coefficient k1 is introduced to verify the influence of the steel fiber content, and the parameters fb, αa, and αb in the formula are reevaluated. A reasonably good agreement between the calculated strength and those obtained from the tests is reported, except for the case of W/B = 0.16 with P.O.52.5 cement. The basic steps for preparations of different RPC strengths are given, which provide a valuable reference to choose appropriate raw materials and mixture ratio design for different strength values.

scholarly journals Influence of Partial Replacement of Micro-Silica by Fly-Ash on Strength Properties of Reactive Powder Concrete

2020 ◽  
Vol 9 (3) ◽  
pp. 2932-2937
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
Mechanical Performance ◽  
Cementitious Materials ◽  
Partial Replacement ◽  
Reactive Powder Concrete ◽  
Experimental Investigations ◽  
Reactive Powder ◽  
Micro Silica

Reactive powder concrete (RPC) is the ultra-high strength concrete made by cementitious materials like silica fumes, cement etc. The coarse aggregates are completely replaced by quartz sand. Steel fibers which are optional are added to enhance the ductility. Market survey has shown that micro-silica is not so easily available and relatively costly. Therefore an attempt is made to experimentally investigate the reduction of micro-silica content by replacing it with fly-ash and mechanical properties of modified RPC are investigated. Experimental investigations show that compressive strength decreases gradually with addition of the fly ash. With 10 per cent replacement of micro silica, the flexural and tensile strength showed 40 and 46 per cent increase in the respective strength, though the decrease in the compressive strength was observed to be about 20 per cent. For further percentage of replacement, there was substantial drop in compressive, flexural as well as tensile strength. The experimental results thereby indicates that utilisation of fly-ash as a partial replacement to micro silica up to 10 per cent in RPC is feasible and shows quite acceptable mechanical performance with the advantage of utilisation of fly-ash in replacement of micro-silica.

scholarly journals Effect of Mix Proportion Parameters on Behaviors of Basalt Fiber RPC Based on Box-Behnken Model

2019 ◽  
Vol 9 (10) ◽  
pp. 2031 ◽  
Author(s):  
Hanbing Liu ◽  
Shiqi Liu ◽  
Shurong Wang ◽  
Xin Gao ◽  
Yafeng Gong
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Basalt Fiber ◽  
Fiber Content ◽  
Reactive Powder Concrete ◽  
Basalt Fibers ◽  
Factors Affecting ◽  
Remarkable Effect ◽  
Mix Proportion ◽  
Reactive Powder

Basalt fibers are widely used in the modification of concrete materials due to its excellent mechanical properties and corrosion resistance. In this study, the basalt fibers were used to modify reactive powder concrete (RPC). The effect of four mix proportion parameters on the working and mechanical properties of basalt fiber reactive powder concrete (BFRPC) was evaluated by the response surface methodology (RSM). The fluidity, flexural and compressive strength were tested and evaluated. A statistically experimental model indicated that D (the silica fume to cement ratio) was the key of interactions between factors, affecting other factors and controlling properties of BFRPC. The increase in basalt fiber content had a remarkable effect on increasing the flexural and compressive strength when D = 0.2. The addition of basalt fiber obviously improved the mechanical properties of RPC. While when D = 0.4, the decrease of fiber content and the increase of quartz sand content could increase the compressive strength.

scholarly journals Effect of different curing conditions on the mechanical properties of reactive powder concrete

2018 ◽  
Vol 162 ◽  
pp. 02014
Author(s):  
Mazin Abdulrahman ◽  
Alyaa Al-Attar ◽  
Marwa Ahmad
Keyword(s):  
Mechanical Properties ◽  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Material Constant ◽  
Hot Water ◽  
Modulus Of Rupture ◽  
Reactive Powder Concrete ◽  
Curing Conditions ◽  
Reactive Powder

Reactive Powder Concrete (RPC) is an ultra-high performance concrete which has superior mechanical and physical properties, and composed of cement and very fine powders such as quartz sand and silica fume with very low water/ binder ratio and Superplasticizer. Heat treatment is a well-known method that can further improve the performance of (RPC). The current research including an experimental study of the effect of different curing conditions on mechanical properties of reactive powder concrete (compressive strength, modulus of rupture and splitting tensile strength), the curing conditions includes three type of curing; immersion in water at temperature of 35 OC (which is considered as the reference-curing situation), immersion in water at temperature of 90 OC for 5 hours daily and curing with hot steam for 5 hours daily) until 28 days according to ASTM C684-99 [8]. This research includes also the study of effect of adding silica fume as percentage of cement weight on mechanical properties of reactive powder concrete for different percentage ratios (5%,10% and 15%). Super plasticizer is also used with ratio of (1.8%) by weight of cementitious material; constant water cement ratio (0.24) was used for all mixes. For each reactive concrete mix, it has been cast into a cubes of (150*150*150) (to conduct the compression test), a cylinders of 150mm diameter with 300mm height (to conduct split test) and prisms of (500*100*100)mm to conduct the modulus of rupture test. The results showed that the best method of curing (according to its enhancing the RPC mechanical properties) is the method of immersion in hot water at temperature 90 OC for the all silica fume percentages, and the best used silica fume percentage was (10%) for the all used curing methods.

Experimental Study on Mechanical Properties of Synthetic Macro-Fiber Reinforced Reactive Powder Concrete

2014 ◽  
Vol 496-500 ◽  
pp. 2402-2406
Author(s):  
Kui He ◽  
Hui Yang ◽  
Fang Fang Jia ◽  
Er Po Wang ◽  
Zhen Bao Lu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Compressive Strength ◽  
Fracture Mechanics ◽  
Flexural Strength ◽  
Fracture Energy ◽  
Ductile Fracture ◽  
Reactive Powder Concrete ◽  
Fiber Reinforced ◽  
Reactive Powder

Workability, strength and fracture mechanics of polypropylene macro-fiber reinforced Reactive powder concrete (RPC) were studied in this work. The results showed that the incorporation of macro-fiber could influence the workability of RPC, the slump of RPC decreased with the increasing of macro-fiber content; compressive strength decreased while splitting strength increased with the increasing of macro-fiber, meanwhile the flexural strength invariant. Macro-fiber could strongly enhance the flexural toughness of RPC and changed the failure mode from brittle to ductile; fracture energy tends to increase linearly with the increasing of macro-fiber.

scholarly journals The Effect of Various Polynaphthalene Sulfonate Based Superplasticizers on the Workability of Reactive Powder Concrete

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Anthony Torres ◽  
Federico Aguayo ◽  
Srinivas Allena ◽  
Michael Ellis
Keyword(s):  
Compressive Strength ◽  
Fresh Concrete ◽  
High Strength ◽  
Reactive Powder Concrete ◽  
Chemical Admixture ◽  
Lower Viscosity ◽  
Reactive Powder ◽  
The Impact ◽  
Polycarboxylate Ether ◽  
High Range

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.

scholarly journals Properties of Reactive Powder Concrete Using Local Materials and Various Curing Conditions

2019 ◽  
Vol 4 (6) ◽  
pp. 74-83 ◽  
Author(s):  
Gamal I. K. ◽  
K. M. Elsayed ◽  
Mohamed Hussein Makhlouf ◽  
M. Alaa
Keyword(s):  
Compressive Strength ◽  
Silica Fume ◽  
High Strength Concrete ◽  
Steel Fiber ◽  
High Strength ◽  
Hot Water ◽  
Reactive Powder Concrete ◽  
Normal Water ◽  
Reactive Powder ◽  
Local Materials

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.

scholarly journals Investigation of the Match Relation between Steel Fiber and High-Strength Concrete Matrix in Reactive Powder Concrete

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1751 ◽  
Author(s):  
Guangyao Yang ◽  
Jiangxiong Wei ◽  
Qijun Yu ◽  
Haoliang Huang ◽  
Fangxian Li
Keyword(s):  
Compressive Strength ◽  
Steel Fiber ◽  
High Strength ◽  
Steel Fibers ◽  
Peak Strength ◽  
Reactive Powder Concrete ◽  
Medium Length ◽  
Reactive Powder ◽  
Concrete Matrix ◽  
Strength And Toughness

This study investigated the strength and toughness of reactive powder concrete (RPC) made with various steel fiber lengths and concrete strengths. The results indicated that among RPC samples with strength of 150 MPa, RPC reinforced with long steel fibers had the highest compressive strength, peak strength, and toughness. Among the RPC samples with strength of 270 MPa, RPC reinforced with short steel fibers had the highest compressive strength, and peak strength, while RPC reinforced with medium-length steel fibers had the highest toughness. As a result of the higher bond adhesion between fibers and ultra-high-strength RPC matrix, long steel fibers were more effective for the reinforcement of RPC with strength of 150 MPa, while short steel fibers were more effective for the reinforcement of RPC with strength of 270 MPa.

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