scholarly journals Role of Polypropylene Fibres in Concrete Spalling Risk Mitigation in Fire and Test Methods of Fibres Effectiveness Evaluation

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3869 ◽  
Author(s):  
Izabela Hager ◽  
Katarzyna Mróz
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Risk Mitigation ◽  
High Strength ◽  
Test Methods ◽  
Reactive Powder Concrete ◽  
Polypropylene Fibres ◽  
Normal Strength ◽  
Reactive Powder ◽  
In Fire

The explosive behaviour of concrete in fire is observed in rapidly heated concrete. The main factors controlling the occurrence of spalling are related to the material’s low porosity and high density as well as the limited ability to transport gases and liquids. Thus, for high-strength, ultrahigh-strength, and reactive powder concrete, the risk of spalling is much higher than for normal-strength concrete. The paper presents the discussion on the leading hypothesis concerning the occurrence of concrete spalling. Moreover, the methods for spalling prevention, such as polypropylene fibre application, which has been found to be an effective technological solution for preventing the occurrence of spalling, are presented. Various tests and testing protocols are used to screen concrete mixes propensity toward spalling and to evaluate the polypropylene fibres’ effectiveness in spalling risk mitigation. The most effective testing methods were selected and their advantages were presented in the paper. The review was based mainly on the authors’ experiences regarding high performance concrete, reactive powder concrete testing, and observations on the effect of polypropylene fibres on material behaviour at high temperature.

Roof Structural System Study with Use of UHPC

2017 ◽  
Vol 259 ◽  
pp. 70-74
Author(s):  
Milan Holý
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Construction Materials ◽  
High Strength ◽  
Structural System ◽  
Total Load ◽  
Dominant Component ◽  
Industrial Buildings ◽  
Normal Strength ◽  
Very High

This paper deals with the roof structural system using prestressed girders made of ultra-high performance concrete (UHPC). One of the aims of this study is to verify whether the option of the UHPC girders could be under certain boundary conditions competitive with the commonly used construction materials. Due to its high strength, UHPC enables the design of the structural elements with the high load bearing capacity and with smaller slenderness compared to normal strength concrete elements. The price of UHPC is currently still very high compared to the normal strength concretes or steel. Therefore, its use for the usual designed structures does not recently seem too economically attractive. The effect of material savings is nonnegligible in the case, that a self-weight of the structure forms dominant component of the total load. In addition to the high strength, UHPC has very high resistance to environmental influences. It is therefore likely, that UHPC could be advantageously applied e.g. for the roofing of industrial buildings of chemical plants with high aggressive environments, because there are high demands on the life cycle of the structure.

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.

scholarly journals Review of The Cement-Based Composite Ultra-High-Performance Concrete (UHPC)

2019 ◽  
Vol 13 (1) ◽  
pp. 147-162 ◽  
Author(s):  
Edwin Paul Sidodikromo ◽  
Zhijun Chen ◽  
Muhammad Habib
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Cementitious Materials ◽  
Vital Role ◽  
Engineering Industry ◽  
Supplementary Cementitious Materials ◽  
Ultra High Performance Concrete ◽  
Strength Concrete ◽  
Normal Strength

Introduction: Ultra-High-Performance Concrete (UHPC) is an advanced type of concrete in the Civil Engineering industry. It is a cement-based composite which exhibits improved mechanical and durable properties showing a high compressive strength of not less than 150 MPa and high tensile strength of not less than 7 MPa. Objective: In this article, a review of the use of a different type of supplementary cementitious materials (SCMs) including fibers is made for obtaining the desired UHPC. Discussion and Conclusion: For this, it is vital to understand the principles of UHPC. UHPC has several advantages over normal strength concrete (NSC) and high strength concrete (HSC) with some commercially ready UHPC’s available, but the use of it is restricted due to the limited design codes. The influence of the curing type also plays a vital role in the overall performance of UHPC.

Mechanical Analysis and Economic Research of RPC Beam Bridge

2015 ◽  
Vol 744-746 ◽  
pp. 784-788
Author(s):  
Xin Peng ◽  
Jian Yang ◽  
Jin Sheng Wang
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Mechanical Analysis ◽  
Economic Research ◽  
Engineering Practice ◽  
Total Cost ◽  
Steel Strand ◽  
Reactive Powder ◽  
Beam Bridge

RPC(Reactive Powder Concrete) is a kind of high performance concrete which has many excellent mechanical properties, e.g. ultra-high-strength, high tenacity and good durability, and it has been applied in engineering practice. However, at present the economic research about RPC bridge is few at home and abroad, which has hindered the development of RPC bridge to some extent. By means of the mechanical analysis and economic research about NC(normal concrete ) beam bridge of pre-stressed steel strand (the span is 40m), RPC beam bridge of pre-stressed steel strand and RPC beam bridge of pre-stressed CFRP(Carbon Fiber Reinforced Polymer) tendon after the sectional optimization has been done, this paper reach the conclusion that the RPC beam bridge can greatly reduce the sectional size of beam bridge and reduce the weight by 23.7% , besides, the total cost of RPC beam bridge of pre-stressed steel strand is almost same with the total cost of NC beam bridge during the entire service period of bridge. Therefore, considering the long-term perspective, the integrated economy of RPC beam bridge of pre-stressed steel strand is good.

scholarly journals Experimental comparative study of reactive powder concrete: mechanical properties and the effective factors

2018 ◽  
Vol 162 ◽  
pp. 04004 ◽  
Author(s):  
Eyad Kadhem ◽  
Ammar Ali ◽  
Sameh Tobeia
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Modulus Of Elasticity ◽  
High Performance ◽  
High Performance Concrete ◽  
Splitting Tensile Strength ◽  
Steel Fibers ◽  
Reactive Powder Concrete ◽  
Concrete Mechanical Properties ◽  
Reactive Powder

Reactive Powder Concrete (RPC) is a type of ultra-high performance concrete, this dense composite material generally characterized by high cement content, high durability, low porosity, low water/cement ratio and in most cases contains steel fibers as new types of concrete appears, further investigation for their mechanical properties are needed. This work aims to give a better understanding of RPC behavior by deriving formulas to calculate the modulus of elasticity and the splitting tensile strength in relation with compressive strength and steel fibers content. This study is based on data obtained from the experimental investigation done in this work and from others pervious works. The parametric study is based mainly on the silica fume content which is used in four different ratios (12 %, 15 %, 20 % and 25 %), the use of micro steel fibers 15 mm in length, 0.2 mm in diameter and aspect ratio of 75 added in ratios of (0 %, 1 %, 1.5 % and 2 %), and water/cement in ratios of (16 %, 18 %, 20 % and 22 %), respectively. The proposed equations show a better behavior in comparison to some available equations that were used in the estimation of modulus of elasticity and splitting tensile strength of reactive powder concrete, the coefficient of variation for the proposed equations (COV) decrease to 10.677% and 10.455% respectively.

Ultra-high performance concrete – properties and technology

2013 ◽  
Vol 61 (1) ◽  
pp. 183-193 ◽  
Author(s):  
T. Zdeb
Keyword(s):  
Mechanical Properties ◽  
Hydrothermal Treatment ◽  
High Performance ◽  
High Performance Concrete ◽  
Qualitative Evaluation ◽  
High Strength ◽  
Ultra High Performance Concrete ◽  
Characteristic Features ◽  
Reactive Powder ◽  
New Generation

Abstract The paper deals with information concerning properties and technology of a new generation cementitious composite i.e. Ultra-High Performance Concrete. High performance here means both high strength and high durability under the influence of environmental factors. This group of composites is mainly represented by Reactive Powder Concretes (RPC), which show both outstanding durability and mechanical properties. Characteristic features of RPC are mainly due to the very low water-cement ratio, which involves application of superplasticizer, significant reduction of aggregate grains size as well as hydrothermal treatment. In the first part of the paper selected properties of RPC are compared to ordinary concrete and to other groups of new generation concrete. Moreover, fundamental technological factors influencing properties of RPC are described as well. The second part deals with the RPC developed at Cracow University of Technology. The presented test results are mainly focused on the influence of steel fibres content on mechanical properties of reactive powder concrete and hydrothermal treatment on composites microstructure. The quantitative and qualitative evaluation of this relationship expand the knowledge of the UHPC technology. Finally, the third part presents the most significant and newest structures which have been erected with the use of RPC

scholarly journals PENGARUH PENAMBAHAN SERAT BAJA TERHADAP SIFAT MEKANIS REACTIVE POWDER CONCRETE

2020 ◽  
Vol 3 (2) ◽  
pp. 49
Author(s):  
Shandy Trisakti paiding Lewa ◽  
Patria Kusumaningrum
Keyword(s):  
High Performance ◽  
Steel Fiber ◽  
High Performance Concrete ◽  
Steel Fibers ◽  
Reactive Powder Concrete ◽  
High Rise ◽  
High Rise Building ◽  
Fine Aggregates ◽  
Reactive Powder ◽  
Column Base

<p><em>As urban growth increase, massive high-rise building construction become a critical solution. In high-rise building, column base may be subjected to very high axial load from the upper stories and may experience very large moment due to the lateral loads. As a result, the column base requires a great deal amount of reinforcement which make it very cramped. In order to prevent honeycomb as the reinforcement gap is narrow yet difficult to provide sufficient vibration during concrete casting, high performance concrete (HPC) may be the solution. One of the HPC innovations is Reactive Powder Concrete (RPC). RPC is a self-compacting type of HPC contains well graded fine and super fine aggregates with cement and pozzolanic material to strengthen the Interfacial Transition Zone (ITZ) between the mortar matrix and fine aggregates. RPC may achieve high compressive strength as the mix uses low water to cement ratio, thus it introduces less void and no coarse aggregates, thus ITZ is stronger. RPC has similar characteristic as concrete, with its brittle behaviour. To avoid the brittle failure of RPC, in this study steel fibers are added into the RPC mixture. This research is conducted to examine the effectiveness of using steel fibers on the mechanical properties of Steel Fiber Reactive Powder Concrete (SFRPC). </em><em>The steel fiber is aimed to increase ductility of tensile strain hardening condition by its multiple crack-bridging behavior.</em></p>

Performance of Reactive Powder Concrete Partial Prestressed Beam-Column Sub-Assemblage Structure System with Partial Prestressed Ratio Exceeds 30%

2016 ◽  
Vol 845 ◽  
pp. 126-131
Author(s):  
Siti Aisyah Nurjannah ◽  
Bambang Budiono ◽  
Iswandi Imran ◽  
Saptahari Sugiri
Keyword(s):  
High Performance ◽  
Structural Engineering ◽  
High Performance Concrete ◽  
Reactive Powder Concrete ◽  
Cyclic Loads ◽  
Test Results ◽  
Ultra High Performance Concrete ◽  
Moment Frame ◽  
Concrete Type ◽  
Reactive Powder

Research on concrete material in many countries resulted a concrete type of Ultra High Performance Concrete (UHPC) which has a high performance in terms of compressive strength, ductility, durability, and modulus of elasticity using Reactive Powder Concrete (RPC). Research on structural engineering using RPC material shows better performance than normal concrete (NC) to resist gravity and cyclic loads. In this study, the experiments were conducted under the combination of constant axial and cyclic loads on the structure of the partial prestressed interior and exterior beam-column subassemblages with partial prestressed ratio value of 31.72% on the beam. The application of cyclic loading was conducted by displacement control based on the ACI 374.1-05. The purpose of this study was to determine the performance of structures based on three moment frame acceptance criteria presented in the ACI 374.1-05. From the test results, the interior and exterior beam-column subassemblage structure systems showed performance that adequated all of these criteria at the drift ratio of 3.50% and 2.20%, respectively.

scholarly journals Reactive Powder Concrete: Durability and Applications

2021 ◽  
Vol 11 (12) ◽  
pp. 5629
Author(s):  
Miguel Ángel Sanjuán ◽  
Carmen Andrade
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Reactive Powder Concrete ◽  
Concrete Durability ◽  
Ultra High Performance Concrete ◽  
Structural Repair ◽  
Potential Applications ◽  
Lower Porosity ◽  
Lower Permeability ◽  
Reactive Powder

Reactive powder concrete (RPC) is an ultra-high-performance concrete (UHPC) developed years ago by Bouygues, with the aim to build strong, durable, and sustainable structures. Some differences can be underlined between the RPC and high-performance concrete (HPC); that is to say, RPC exhibits higher compressive and flexural strength, higher toughness, lower porosity, and lower permeability compared to HPC. Microstructural observations confirm that silica fume enhances the fiber–matrix interfacial characteristics, particularly in fiber pullout energy. This paper reviews the reported literature on RPC, and it offers a comparison between RPC and HPC. Therefore, some RPC potential applications may be inferred. For instance, some examples of footbridges and structural repair applications are given. Experimental measurements on air permeability, porosity, water absorption, carbonation rate, corrosion rate, and resistivity are evidence of the better performance of RPC over HPC. When these ultra-high-performance concretes are reinforced with discontinuous, short fibers, they exhibit better tensile strain-hardening performance.

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