scholarly journals Microstructure and Mechanical Property Evaluation of Dune Sand Reactive Powder Concrete Subjected to Hot Air Curing

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 41
Author(s):  
Sara Ahmed ◽  
Zin Mahaini ◽  
Farid Abed ◽  
Mohammad Abdul Mannan ◽  
Mufid Al-Samarai
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
Microstructural Analysis ◽  
Point Of View ◽  
Engineering Properties ◽  
Reactive Powder Concrete ◽  
Dune Sand ◽  
Hot Air ◽  
Reactive Powder

The use of different sustainable materials in the manufacture of ultra-high-performance concrete (UHPC) is becoming increasingly common due to the unabating concerns over climate change and sustainability in the construction sector. Reactive powder concrete (RPC) is an UHPC in which traditional coarse aggregates are replaced by fine aggregates. The main purpose of this research is to produce RPC using dune sand and to study its microstructure and mechanical properties under different curing conditions of water curing and hot air curing. The effects of these factors are studied over a long-term period of 90 days. Quartz sand is completely replaced by a blend of crushed and dune sand, and cement is partially replaced by using binary blends of ground granulated blast furnace slag (GGBS) and fly ash (FA), which are used alongside silica fume (SF) to make a ternary supplementary binder system. Microstructural analysis is conducted using scanning electron microscopy (SEM), and engineering properties like compressive strength and flexural strength are studied to evaluate the performance of dune sand RPC. Overall, the results affirm that the production of UHPC is possible with the use of dune sand. The compressive strength of all mixes exceeded 120 MPa after 12 h only of hot air curing (HAC). The SEM results revealed the dense microstructure of RPC. However, goethite-like structures (corrosion products) were spotted at 90 days for all HAC specimens. Additionally, the use of FA accelerated the formation of such products as compared to GGBS. The effect of these products was insignificant from a mechanical point of view. However, additional research is required to determine their effect on the durability of RPC.

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.

Dosage of Metakaolin in High Performance Concrete

2016 ◽  
Vol 722 ◽  
pp. 311-315 ◽  
Author(s):  
Michal Ženíšek ◽  
Tomáš Vlach ◽  
Lenka Laiblová
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
Rheological Behaviour ◽  
Economic Benefits ◽  
Point Of View ◽  
Optimal Dosage ◽  
Higher Doses

This article deals with optimal dosage of metakaolin as addition in high performance concrete. The main criteria for assessing the optimal dosage of metakaolin was compressive strength, rheological behaviour and economic benefits. Metakaolin was added to the mixture of high performance concrete in the range from 0 to 25% weight of cement. The comparison of metakaolin and microsilica, which is often used by concrete producers due to its excellent properties, is also performed in this article. The experiments showed that using metakaolin as addition in high performance concrete affects the compressive strength and rheological behaviour positively. While the compressive strength increases especially at lower doses of metakaolin and at higher doses remained unchanged, changes in rheological behaviour were most obvious at the higher doses. From this point of view, it is possible to recommend a higher dose of metakaolin.

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.

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>

Effects Superplasticizer Type and Dosage on The Properties of Reactive Powder Concrete

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Eethar Thanon Dawood
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Positive Impact ◽  
Physical And Mechanical Properties ◽  
Reactive Powder Concrete ◽  
Dry Density ◽  
Chemical Admixture ◽  
Main Components ◽  
Reactive Powder ◽  
Saturated Surface

Superplasticizer is one of the most common types of chemical admixtures used in the mortar or concrete, especially that characterized high performance like Reactive powder concrete. Recently, the chemical admixture is considered as one of the main components of cement-based products due to it has a significant role to improve the physical and mechanical properties generally. Therefore, the experimental work of this research has been an attempt to study the influence of two types of superplasticizers with different dosages on the properties of reactive powder concrete. The workability, compressive strength, and saturated surface dry density of reactive powder concrete used two types of chemical admixture(superplasticizer) individual and in combination have been studied and compared together. The results indicated that the use of superplasticizer type ViscoCrete-5930 in individual or combination with superplasticizer type KUT PLAST PCE600 has a positive impact on the properties of reactive powder concrete especially its flowability and compressive strength. Keywords:Reactive powder concrete; Superplasticizer; Flowability; Compressive strength; Saturated surface dry density;

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.

scholarly journals Study of the Influence of the Aggressive Environment on the Behavior of Reactive Powder Concrete

2021 ◽  
Vol 2 (1) ◽  
pp. 7-12
Author(s):  
Mounira Chadli
Keyword(s):  
Compressive Strength ◽  
Iron Ore ◽  
Major Effect ◽  
Reactive Powder Concrete ◽  
Dune Sand ◽  
Steam Curing ◽  
Curing Conditions ◽  
Test Pieces ◽  
The Family ◽  
Reactive Powder

Reactive Powder Concrete (RPC) currently represents the family of cementitious matrix materials with properties the most exceptional mechanics and durability. This study aims to investigate the physico-mechanical properties, and the durability in a sulphated environment of a reactive powder concrete using materials available in our region, we have integrated materials rich in silica (slag, silica fume and crushed quartz) in Portland cement with 15, 23 and 25%, respectively. After The remove of the specimens from the mold and place the RPC in the curing box under steam curing conditions of 90 ° C for 72h, let them cool naturally for 24 h, the test pieces are immersed in water at 20 ° C, the specimens are broken in flexion and compression. From this study we can make the following conclusions: The incorporation of additions increases the compressive and flexural tensile strengths, which gives an improvement in the compactness of the mixtures by the pozzolanic effect of these last, by removing the particle size phase in the RPC and the affluence of dune sand (southern Algeria) and slag (industrial waste from the iron ore blast furnace), because Na2SO4 has a major effect on the compressive strength notably for non-fibrous formulations. NaOH improve the compressive strength for all formulation.

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.

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