A semi-empirical study of penetration of shaped charge jet into high and ultra-high strength reactive powder concrete targets

2020 ◽  
pp. 095440622095249
Author(s):  
Qifeng Zhu ◽  
Zhengxiang Huang ◽  
Qiangqiang Xiao ◽  
Xudong Zu ◽  
Xin Jia
Keyword(s):  
Compressive Strength ◽  
Penetration Depth ◽  
Cavity Growth ◽  
High Strength ◽  
Shaped Charge ◽  
Reactive Powder Concrete ◽  
Jet Velocity ◽  
Reactive Powder ◽  
Semi Empirical ◽  
Shaped Charge Jet

In this study, a semi-empirical model was proposed to calculate the penetration depth and cavity diameters generated by shaped charge jet into high and ultra-high strength concrete (H&UHSC) targets. A recently proposed axial penetration equation and the two-step mechanism of cavity growth were employed to determine the analysis. The predictions were validated with reference to the experiments conducted using a kind of H&UHSC named reactive powder concrete (RPC). Furthermore, the influences of the RPC compressive strength and the jet velocity on the penetration were analyzed. The results showed that the RPC targets had good protection efficiency for both penetration depth and cavity diameters as the compressive strength approaches approximately 250∼280MPa. Moreover, the radial cavity growth efficiency increased linearly with the increase of the jet velocity, while the axial penetration efficiency increased rapidly when the jet velocity was 1.0∼4.0km/s and reached the maximum at 4.0∼7.0km/s and tended to be stable as the jet velocity increased to greater than about 7.0km/s.

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.

scholarly journals Experimental Study on Reactive Powder Concrete under Flexural Loading

2018 ◽  
Vol 7 (2.24) ◽  
pp. 552
Author(s):  
Jeganmurugan P ◽  
Rakesh Senthil Kumar G V ◽  
Sivasharmina M ◽  
Sowmiya S ◽  
Vasanthan M
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Silica Fume ◽  
High Strength ◽  
Reactive Powder Concrete ◽  
Split Tensile Strength ◽  
Mix Proportion ◽  
Compressive Strength Test ◽  
Trial And Error Method ◽  
Reactive Powder

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.   

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.

scholarly journals Shear performance of single-keyed dry joints between reactive power concrete and high strength concrete in push-off tests

2020 ◽  
Vol 103 (2) ◽  
pp. 003685042092864
Author(s):  
Jiahui Feng ◽  
Weibin Liang ◽  
Haibo Jiang ◽  
Chengwang Huang ◽  
Jingyuan Zhang
Keyword(s):  
Compressive Strength ◽  
High Strength ◽  
Shear Capacity ◽  
Steel Fibers ◽  
Reactive Powder Concrete ◽  
Concrete Compressive Strength ◽  
Strength Concrete ◽  
Shear Key ◽  
Shear Performance ◽  
Reactive Powder

Shear key joints are commonly used in constructions of precast concrete segmental bridges. Most researches focused on shear performance of the dry joints with the identical-strength concrete, leaving a research gap on that of composite joints between different concrete segments. This research aims to investigate shear behavior of shear key joint between reactive powder concrete and high strength concrete. Totally 12 specimens of single-keyed dry joint were tested, with the parameters of concrete compressive strength, steel fibers, and confining stress. The experimental results indicated that shear failure was observed, but crushing phenomenon occasionally occurred in composite joints in testing, which was confirmed by stress distribution from numerical simulation. In terms of shear capacity of composite joint, peak shear loads of reactive powder concrete specimens without steel fibers were enhanced by 10%–12% as increasing of concrete compressive strength, while those with steel fibers achieved 22%–25% enhancement. Nevertheless, a slight reduction of normalized shear strength was obtained because of its lower volume fraction of coarse aggregate. In numerical simulation, as increasing the concrete compressive strength of convex part, peak shear load was enhanced, but the increment rate of peak shear load decreased. Shear design formulae underestimated shear capacity of reactive powder concrete specimens with steel fibers, but the models proposed by Buyukozturk and Rombach gave accurate predictions on those without steel fibers.

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%

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