Experiment and validation of local bearing capacity for reactive powder concrete confined with high-strength spirals

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Sheng Li ◽  
Wenzhong Zheng ◽  
Wei Zhou ◽  
Zhisheng Jiang ◽  
Ying Wang
Keyword(s):  
Bearing Capacity ◽  
High Strength ◽  
Reactive Powder Concrete ◽  
Reactive Powder

Effects of Silica Fume Addition on the Spalling Phenomena of Reactive Powder Concrete

2012 ◽  
Vol 174-177 ◽  
pp. 1090-1095 ◽  
Author(s):  
Kai Pei Tian ◽  
Yang Ju ◽  
Hong Bin Liu ◽  
Jin Hui Liu ◽  
Li Wang ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Vapor Pressure ◽  
Silica Fume ◽  
High Strength Concrete ◽  
High Strength ◽  
Reactive Powder Concrete ◽  
Spalling Resistance ◽  
Explosive Spalling ◽  
Strength Concrete ◽  
Reactive Powder

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.

Blast-resistance of ultra-high strength concrete and reactive powder concrete

2017 ◽  
Vol 3 (2) ◽  
pp. 98-104 ◽  
Author(s):  
Tae-Hee Lee ◽  
Dal-Hun Yang ◽  
Min-Jae Kwon ◽  
Jang-Ho Jay Kim
Keyword(s):  
High Strength Concrete ◽  
Blast Resistance ◽  
High Strength ◽  
Reactive Powder Concrete ◽  
Strength Concrete ◽  
Reactive Powder

Toughness and characterization of reactive powder concrete with ultra-high strength

2009 ◽  
Vol 52 (4) ◽  
pp. 1000-1018 ◽  
Author(s):  
Yang Ju ◽  
HongBin Liu ◽  
Jian Chen ◽  
YuDan Jia ◽  
PeiHuo Peng
Keyword(s):  
High Strength ◽  
Reactive Powder Concrete ◽  
Reactive Powder

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 Dynamic Constitutive Model for Reactive Powder Concrete with Standard Curing

2018 ◽  
Vol 2 (1) ◽  
Keyword(s):  
Constitutive Model ◽  
Strain Rate ◽  
Steel Fiber ◽  
High Strength ◽  
Reactive Powder Concrete ◽  
Strengthening Effect ◽  
Compression Tests ◽  
Softening Effect ◽  
Impact Compression ◽  
Reactive Powder

In view of the disadvantages of steam curing of reactive powder concrete (RPC), RPC with standard curing (SCRPC) is proposed. SC-RPC is an ultra-high strength concrete material prepared with high strength cement, silica fume, and gypsum by standard curing. In this study, quasi-static and impact compression tests were performed to investigate the mechanical properties of SC-RPC. The results show that steel fiber and the strain rate significantly affect the compression performance. Nevertheless, the Holmquist–Johnson–Cook (HJC) constitutive model is mainly used to analyze the dynamic response of brittle materials, such as common concrete, under shock and impact. Therefore, based on the quasi-staticand impact compression tests and the HJC constitutive model for concrete, by analyzing the steel fiber strengthening effect under quasi-static uniaxial compression, strain rate hardening, and the damage softening effect under SHPB impact compression, the steel fiber strengthening factor Kf , dynamic increase factor DIF, and revised damage variable D are introduced, and a modified HJC constitutive model for RPC with standard curing is proposed.

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.

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.

Influence of Axial Compression Ratio on Seismic Behavior of Reactive Powder Concrete (RPC) Beam-Column Joints

2014 ◽  
Vol 597 ◽  
pp. 312-315 ◽  
Author(s):  
Yan Zhong Ju ◽  
Chun Yu Li ◽  
De Hong Wang
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Compression Ratio ◽  
Seismic Behavior ◽  
Ultimate Bearing Capacity ◽  
Reactive Powder Concrete ◽  
Element Analysis ◽  
Axial Compression Ratio ◽  
Reactive Powder ◽  
Axial Compressive Ratio

To explore the influence of axial compressive ratio on seismic behavior of reactive powder concrete(RPC) beam-column joints,this paper carry out RPC beam-column joints nonlinear finite element analysis,using software ABAQUS.The effect of different axial compression ratio on the ductility,energy dissipation capacity and bearing capacity are studied,based on hysteretic curves and skeleton curves of the components.The results show that,with the increase of axial compression ratio,skeleton curves of the components tend to be steep when the vertical load of beam ends exceed the peak point.The ultimate bearing capacity of the components are improved with the increasing of axial compression ratio which is less then 0.6,while the ultimate bearing capacity show a opposite trend when the axial compressive ratio exceed 0.6.

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