Reactive Powder Concrete Research Articles

Experimental investigation of non-prismatic hybrid plane frame containing glass fiber reactive powder concrete and conventional concrete under static load

Experimental investigation of non-prismatic hybrid plane frame containing glass fiber reactive powder concrete and conventional concrete under static load

Experiments and analytical model for axial strength of FRP-reinforced reactive powder concrete circular columns under axial compression

Although various experimental studies have been performed in the literature to explore the behavior of glass fiber reinforced polymer (glass-FRP) reinforced conventional concrete columns, no study focused on the axial performance of glass-FRP-reinforced reactive powder concrete (RPC) columns (GRPC columns) subjected to compression. Therefore, the current struggle investigates the behavior of nine GRPC columns through experimental testing, finite element analysis (FEA), and theoretical models on the circular samples with 250 mm diameter and 1000 mm length under axial compression. Steel fibers are added to RPC to minimize brittleness and to improve the strength of RPC. Moreover, a parametric study is planned to utilize the suggested FEA model for exploring the effects of various variables of GRPC columns on axial structural performance. The test findings showed that the GRPC columns become more ductile with the addition of fibers and a reduction in the vertical distance between the glass-FRP hoops/ties. The failure of GRPC columns occurred in the middle region of the samples with the delayed spalling of the concrete cover. The suggested analytical model based on the 600 data points presented higher accuracy than previous theoretical models. The recommended FEM for the axial capacity and associated axial shortening of examined samples portrayed errors of 3.25% and 4.65%, respectively. Considering the axial contribution of glass-FRP longitudinal bars and the transverse confining mechanism of FRP stirrups, the recommended theoretical model for the axial capacity of GRPC column samples performed well for the test findings of the examined samples with R2 = 0.842, MSE = 139.559, MAE = 195.538, and RMSE = 200.756.

The Structural Performance Of Short Circular Concrete Columns Made With Reactive Powder Concrete And Externally Reinforced With Textile Fabric

In the current laboratory investigation, the behavior of hollow circular concrete columns exposed to vertical compressive force is examined. The columns are externally strengthened with Glass Fibre Reinforced Polymer bars and textile fabric (one layer and two layers). The longitudinal reinforcement cast using concrete Reactive Powder Concrete has an outer diameter of (250 mm), a bore diameter of (100 mm), and a length of (1000 mm). The number of textile layers (one or two layers) is one of the main variables used in this experiment study. According to the experimental findings, the hollow circular concrete columns raised the tested concrete columns' bearing capacities by roughly (9.93%) and (17.8%), respectively, after the specimens were allowed to cure for 28 days. This improvement was made for strengthening columns that were subjected to compressive loads and had one or two layers of textile fabric.

Effects of Multi-Walled Carbon Nanotubes and Recycled Fine Aggregates on the Multi-Generational Cycle Properties of Reactive Powder Concrete

In order to investigate the effect of multi-walled carbon nanotubes (MWCNTs) on the recyclable properties of multi-generation recycled concrete, the physical properties of multi-generation recycled fine aggregate and the mechanical properties of multi-generation recycled concrete with different dosages of MWCNTs were tested, and the enhancement mechanism was analyzed by scanning electron microscopy (SEM). The results showed that the apparent density of multi-generation recycled fine aggregate with 0.05 wt% MWCNTs was increased by 1.04~2.03%, the crushing value was decreased by 38.21~49.45%, the compressive strength of the concrete prepared by it was increased by 11.11~18.96%, the splitting tensile strength was increased by 10~43.94%, the flexural strength was increased by 13.62~22.23%, and the mechanical properties were analyzed by scanning electron microscopy (SEM). Combined with the scanning electron microscope image analysis, the MWCNTs can fill the pores inside the specimen, bridge the cracks, and retard the decrease in concrete strength after multi-generation recycling.

Sustainable use of ultrafine recycled glass in additive manufactured (3D printed) reactive powder concrete

Recycled Ultrafine Glass Powder (UFGP) is used to create Reactive Powder Concrete (RPC), a construction material with outstanding qualities for 3D printed concrete (3DPC) applications. Due to its pozzolanic characteristics and particle size, UFGP increases the strength of concrete. By partially replacing cement, using UFGP in 3DPC might reduce waste from the glass industry, advance sustainability, and make it possible to build durable, environmentally friendly, and reasonably priced structures. This study investigates the impact of incorporating 10 μm UFGP as a cement replacement, at rates ranging from 0% to 25%, on the fresh performance, constructability, and mechanical properties of 3DP-RPC. Results showed an increase of slump by 27.54% with 25% UFGP. Mix with 20% UFGP showed a comparable compressive and flexural strength with the control sample. Therefore, incorporating GP in concrete not only enhances its properties but also significantly reduces its carbon footprint. This innovative approach has considerable potential in promoting environmental sustainability in the construction industry.

Numerical Study of Composite Concrete Castellated Double Channel Beams with Strengthening Techniques

Current numerical research was devoted to investigating the effect of castellated steel beams without and with strengthening. The composite concrete asymmetrical double hot rolled steel channels bolted back to back to obtain a built-up I-shape form are used in this study. The top half part of the steel is smaller than the bottom half part, and the two parts were connected by bolting and welding. The ABAQUS/2019 program employed the same length and conditions of loading for four models: The first model is the reference without castellated and strengthening; the second model was castellated without strengthened; the third model was castellated and strengthened with reactive powder concrete encased in the steel web, and the fourth model was castellated and strengthened with reactive powder concrete and lacing steel rebar's welded diagonally on two sides of the steel web. According to the Numerical results, there was an increase in ultimate load capacity compared to the reference model of about 22.74%, 51.65%, and 77.98% in the second, third, and fourth models, respectively; also, there is a reduction in deflection of 55.52%, 58.74, and 60.55% in the second, third, and fourth models, respectively, compared to the level deflection at ultimate load for the reference model, with an increase in stiffness and ductility. In comparison to the I section, the fabrication of a castellated steel beam from the double channel is more cost-effective in terms of cutting steel loss at the ends of the castellated beam, this is due to the feature of rotation and reflection of the steel channel section during cutting and forming to castellated shape.

EFFECT OF USING WASTE FIBERS ON THE STRENGTH PROPERTIES OF SUSTAINABLE REACTIVE POWDER CONCRETE

A bulk volume of waste tires, an underrated global resource, is disposed of in landfills worldwide. Extracting recycled steel fibers from these tires is an evolving trend nowadays. Reactive-Powder Concrete (RPC), the most recent generation of concrete produced in the early 1990s and possessing extremely high mechanical strength criteria, is a modified form of high-performance Concrete. This study looked into how the type and volume proportion of new and waste steel fibers affected the compressive, flexural, and impact strengths 
 of RPC when it was curried at high temperatures. Steel fibers (new and waste tire fibers) with volume fractions of 1%, 1.5%, and 2% were used to create RPC. It was clear that increasing the amount of steel fiber had a beneficial effect on compressive, flexural, and impact strengths. Also, the results showed that the outcomes of RPC having steel fibers sourced from end-of-life tires are similar to those of industrial steel fibers.

Influence of Ferronickel Slag 3 Powder as Supplementary Cementitious Material in Strength and Durability of Reactive Powder Concrete

Influence of Ferronickel Slag 3 Powder as Supplementary Cementitious Material in Strength and Durability of Reactive Powder Concrete

Effect of Steel Fiber Type and Curing Regimen on the Mechanical Properties of Reactive Powder Concrete

Reactive powder concrete (RPC) can provide enhanced mechanical properties and durability compared to conventional concrete. RPC has been developed in this study using locally available materials. Six types of steel fibers and three curing regimens were considered to examine their effect on the mechanical properties of RPC. Steel fibers were incorporated by 1% and 2% of the total volume of mixtures. Generally, the experimental results showed that 1% steel fibers enhanced the compressive, flexural, and splitting tensile strengths by 23.6%, 65.1%, and 72.7%, respectively, compared to control mixtures (no fibers). On the other hand, the 2% of fibers improved the compressive, flexural, and tensile strengths by 39.2 %, 155.0%, and 191.7%, respectively. The curing regimen, which consisted of 2 days at 60°C and 3 days at 90°C, followed by 21 days of moist curing at 21°C, indicated the ultimate enhancement of the mechanical properties of RPC. Also, hooked fibers appeared to enhance flexural strength and tensile strength compared to other types of fibers.

Impact Resistance of Sustainable Reactive Powder Concrete and Reinforced Concrete Slabs

In this paper, the behavior of sustainable reactive powder concrete after the impact load test was examined. The sustainable reactive powder concrete mixture contains 10% steel slag substituting CEM I 52.5 N cement and 4% waste fibers. Reinforced and unreinforced concrete slabs were produced from sustainable reactive powder concrete [SRPC]. A repeat impact load was applied to the reinforced concrete slabs reinforced with steel reinforcement mesh by dropping a constant weight impact head until the slabs failed. The first crack damage and failure damage on the slabs were determined, and the data obtained in both cases were analyzed. It has been determined which number of falls caused the first crack damage and failure damage to the slabs. The acceleration data of the slabs with respect to time and the deflection values with respect to time were recorded in the experiment. The input energies of the slabs were evaluated according to the first crack damage and failure damage. As a result, as the fiber content in the slabs increases, the energy absorption capacity increases. The input energy of the fiber-doped and reinforced concrete slabs reached 2094 joules in the event of failure damage and absorbed about 2 times more energy than the non-fiber and reinforced concrete slabs.

Cracking characteristics evaluation for reinforcement basalt fiber reactive powder concrete beam using acoustic emission

New types of fibers such as basalt fibers are gradually being used to reinforce cement-based concrete materials. To provide a basis for the further popularization of basalt fibers and basalt fiber reinforced reactive powder concrete (BFRPC) materials, the bending mechanical properties and fracture properties of BFRPC beams were investigated by innovatively applying four-point bending test and multiple acoustic parameter analysis methods. On the one hand, the load vs. displacement curve and crack pattern of reinforcement BFRPC beam were obtained from the four-point bending test. On the other hand, Acoustic emission (AE) technology was used to monitor the cracking process of reinforcement BFRPC beam under four-point bending load, and the AE signal was analyzed to illustrate the cracking characteristics of reinforcement BFRPC beam. The results revealed that AE hits, amplitude, counts, duration, and energy have a similar changing trend with bending load. Cumulative hits and cumulative energy are positively linearly related to the displacement and quadratically related to the sum of crack widths, and the correlation coefficients are all above 0.95. Besides, the cracking process of reinforcement BFRPC beam can be divided into four stages by the variation of AE basic parameters with bending load. The main rebars yielding is an important turning point of the crack characteristic of reinforcement BFRPC beam. AE signal data varies greatly in different locations, and it has an obvious advantage to detect the formation of invisible cracks. The results of predicting concrete damage and cracking by AE signal data are consistent with the experimental phenomenon. The low-stress brittle fracture caused by tensile fracture was reduced, and the tensile resistance and flexural bearing capacity of the reinforcement BFRPC beam were increased. The results obtained in this paper support the damage assessment and structural health monitoring for cement base concrete materials under bending load.

Investigation of dynamic compression properties of basalt fibre reactive powder concrete

Basalt fibre reactive powder concrete (BFRPC) was prepared by incorporating basalt fibres (BFs) instead of steel fibre into reactive powder concrete. In this study, the impact resistance of BFRPC was experimentally and numerically analysed at different strain rates (101–102 s−1). The 75 mm dia. split-Hopkinson pressure bar was used for impact compression tests and the finite-element software LS- Dyna was used for numerical simulation analysis. The results showed that the high-strength BFRPC has an obvious strain rate effect and the dynamic increase factor (DIF) of compressive strength increases logarithmically with strain rate. Meanwhile, the parameters of the Comité Euro-international du Béton (CEB) model were refitted and the relationship between strain rate and DIF was established. By using the Holmquist−Johnson−Cook material constitutive model (HJC model), the stress−strain curves and failure patterns obtained were consistent with the experimental results. The incorporation of BFs significantly improves the deformation properties of BFRPC.

An experimental investigation into the characteristics and performance of reactive powder concrete to choose the ideal mix

reactive Powder Concrete (RPC) originated in the early 1990s as a cutting-edge concrete material renowned for its outstanding strength, durability, and ductility. Its remarkable durability attributes stem from a low water-cement ratio, high density, and elevated strength. With high ductility, RPC exhibits significant deformation capabilities before reaching failure. Additionally, its low porosity contributes to reduced material permeability, enhancing resistance against chemical attack and water infiltration. The primary goal of this experimental investigation is to choose an ideal mix for reactive powder concrete after implementing several experimental mixes based on mixing ratios implemented during previous studies to choose the optimal mix. Subsequently, the chosen mixture underwent testing at 7 days to assess its behavior and mechanical properties, utilizing six standard cylindrical specimens (10*20) cm and six cubes (15*15) cm. The results demonstrated a substantial increase in the ultimate compressive strength of the (RPC) specimen by 72% compared to the Normal Concrete (NC) specimen. Moreover, the tensile strength of the RPC exhibited a 35.4% increase compared to the (NC) specimen. The stress-strain analysis indicated a remarkable 118% increase in the (RPC) specimen's maximum stress compared to the (NC) counterpart. In contrast, the strain values for ordinary concrete rose by 22.5% at the point of maximum stress compared to the RPC specimen. Specifically, the tensile stress of the (RPC) specimen increased by 10% compared to the (NC), accompanied by a 29% uptick in tensile strain for the RPC specimen at the point of maximum stress. Furthermore, the (RPC) specimen demonstrated a 38.2% increase in the Modulus of Elasticity and a 35.7% increase in Poisson's ratio compared to the (NC) specimen.

Investigation of strength and durability performance of concrete with varying crude oil waste ratios

The influence of crude oil (CRO) pollution on concrete compressive strength and durability performance is evaluated in this work. Due to CRO contamination on its compositions, concrete exposed to oil-prone areas may lead to considerable changes in its properties. Experimental work has been conducted, and several cubes of concrete with varying ratios of CRO pollution were treated to study the impact of pollution on the mechanical characteristics of the concrete. The current research methodology consists of preparing contaminants by mixing CRO in different ratios with fine aggregates and mixing it with other raw materials to produce polluted concrete. Twelve CRO ratios (0, 1, 2, 2.5, 3, 4, 5, 6, 10, 15, 20, and 25%) were utilized to test typical concrete slump, compressive, and tensile strength. Then, the same concrete procedure and testing were repeated by utilizing 2% CRO in the case of reactive powder concrete. The chemical test was also utilized to identify the changes in concrete composition for the three samples (standard concrete without CRO, standard concrete with 2% CRO, and reactive powder concrete sample). The experimental tests illustrated that a ratio of 2% of CRO in standard concrete improves compressive and tensile strength, while utilizing the same ratio in reactive powder concrete reduces strength. On the other hand, utilizing 2% CRO illustrates that the internal sulfate amount has been increased for both normal and reactive powder concrete compared with normal concrete samples without CRO, which refers to a reduction in concrete durability.

Study on the Compressive Properties of RPC Restrained by CFRP Sheet under Low-Temperature Curing

Abstract To address the problem of significant degradation of compressive properties of reactive powder concrete (RPC) after freezing during the curing period in a low-temperature environment, carbon fiber–reinforced polymer (CFRP) was used to restrain RPC specimens with carbon fiber filament content of 0 or 1 %, and axial compression tests were performed after low-temperature curing (20°C, −5°C, −15°C, and −25°C). The effects of temperature, restraint, and carbon fiber filament content on the compression properties of the RPC were analyzed. Results of the analysis showed that the mechanical properties of RPC under compression decreased with decreasing curing temperature. The use of CFRP sheets for the restraint of RPC specimens and the addition of carbon fiber filaments can both increase the ultimate load capacity of RPC specimens at each curing temperature, and the specimens were relatively intact after damage. With the addition of carbon fiber filaments, which can slow down the rate of decay of load capacity as curing temperature decreases, the degree of load capacity improvement is greater the lower the temperature. The degree of load capacity increase of the CFRP sheet decreases with decreasing temperature because of the weakening of the epoxy resin adhesive bond strength in the CFRP sheet at low temperatures. Both CFRP sheets and carbon fiber filament can increase the compressive pre-crack energy absorbed by RPC at each of the temperatures and can increase the toughness of RPC at low temperatures.

Performing laboratory study of the behavior of reactive powder concrete on the shear of RC deep beams by the drilling core test

Abstract In the past decade, it has been observed that the applications of modern materials have developed a lot, especially effective reactive powder concrete (RPC), due to its superior performance properties. As a result of the superior resistance of RPC, it will give a longer construction life with less maintenance and more resistance to various environmental conditions and exhibits high-performance features such as high porosity, very high strength, and excellent corrosion resistance. The parameters studied in the present research were used to investigate the effect of maximum load, deflection, tensile and strain of concrete, first shear crack, crack pattern, and crack width. Considering the aforesaid cause and objective, one specimen of RPC RC deep beams has a rectangular cross-section of 150 mm in width, 500 mm in depth, and a total length of 1.2 m. One control specimen was tested for comparison. Moreover, 12 control specimens including cylinders and cubes were cast and tested to obtain the mechanical properties of the normal and RPC deep beams. Following the specimens’ processing, they were subjected to two concentrated load pressure tests through a hydraulic jack. Based on the results, the ultimate strength, deflection, and first shear crack capacity for the reactive powder concrete deep beam (RPCDB) have increased by 68, 10.5, and 62.5%, respectively, compared with concrete deep beam (CDB). Moreover, with respect to the width, the delay in the appearance of the first shear crack was reduced by 11 and 78%, respectively, compared with CDB at 65% of the final shear load. In addition, regarding the stress-strain results, RPCDB has increased by 118% at the maximum stress compared with CDB and in contrast, the strain scores for CDB increased by 22.5% at maximum stress compared to RPCDB.

A Study on Chloride Corrosion Resistance of Reactive Powder Concrete (RPC) with Copper Slag Replacing Quartz Sand under Freeze-Thaw Conditions.

In order to study the influence of freeze-thaw cycles on chloride ion corrosion resistance of RPC with copper slag (CS) instead of quartz sand (QS), the 28d uniaxial compressive strength (UCS) of CSRPC with a different CS substitution rate was investigated by unconfined compression tests. The electric flux test method was used to study the chloride ion diffusion resistance of CSRPC after freeze-thaw cycles, and the pore size distribution was obtained through the nuclear magnetic resonance (NMR) method. Then, a mathematical relationship between the chloride ion diffusion coefficient and the pore fractal characteristic parameter T was established to study the effect of freeze-thaw cycles on chloride ion diffusion. Finally, SEM/EDS, XRD, and DTG methods were combined to study the influence of the distribution of Friedel's salts generated after freeze-thaw cycles on chloride ion diffusion in CSRPC. The results indicate that CS has a micro aggregate effect and pozzolanic activity, which can effectively improve the chloride ion diffusion resistance of CSRPC after freeze-thaw cycles. In addition, the electric flux of CSRPC decreases with the increase in freeze-thaw cycles, and the chloride diffusion coefficient is closely related to the pore fractal dimension.

Mechanical Properties and High Temperature Performance of Sustainable Reactive Powder Concrete Containing Waste Glass

At present, it is a challenge to produce a high performance reactive powder concrete (RPC) from local available materials due to the least costly components of a conventional concrete are eliminated by more expensive elements such as the silica fume and steel fibers. In the other hand, million tons of glass is being dumped every year all over the world. More than 75% of glass composition is basically silica and reported to having a pozzolanic reaction. Thus, glass is potentially suitable material as replacement materials for the RPC mixture. In our work, waste glass powder (WGP) was used to completely replace silica fume. Compressive strength, splitting tensile strength, flexural strength and elastic modulus measurements were reported along with the density and colour of the RPC produced. The highlight of this study is on the assessment of the RPC at high temperature tested by direct burning at 600˚C. This had addressed to a very limited reported finding on the high temperature performance of RPC utilizing waste materials. It was found that, RPC containing waste glass powder changes the colour of RPC from darkish grey to light grey. Adding waste glass powder had reduced the density of RPC by (0.05) gm/cm3. Using waste glass powder instead of silica fume had also improves the mechanical properties of RPC. However, there is no effect of adding waste glass powder in solving the spalling problem of RPC at high temperature up to 600˚C. This paper reports finding on the mechanical properties and high temperature performance of sustainable RPC that utilize waste glass powder in total replacement for the silica fume. This is carried out as an effort to address the high cost of the material used in the ordinary RPC and to enhance the recycling of local waste glass.

Mechanical Behavior of Large Symmetric Fiber Reinforced Polymer-Reactive Powder Concrete Composite Tanks with Floating Tops

In order to investigate the mechanical behavior of FRP-reactive powder concrete composite tanks with floating tops (FRPCTs) subjected to gravity, twenty-two full-scale FRPCTs were designed with varying parameters for the inner diameter of the storage tank (D) and the thickness of the reactive powder concrete (tc). Based on nonlinear constitutive models and the contact of the materials, and considering tank–liquid coupling, three-dimensional finite element refined models of FRPCTs were established under gravity with ADINA8.5 finite element software, and finite element models of FRPCTs under gravity were verified based on theoretical frequency formulae and existing static tests. Then, the influence of the regularity of different parameters on the equivalent stress, hoop stress, radial stress, and axial stress of the FRPCTs was obtained, and the stress distributions of FRPCTs were clearly described. The results show that the natural frequency of FRPCTs increases gradually with an increase in the height of the tank liquid (Hw); however, the natural frequency of FRPCTs reduces with an increase in D. The equivalent stress, hoop stress, radial stress, and axial stress of the FRP plate and RPC decrease slowly with an increase in tc. The axial stress of the inner RPC increases with an increase in D. The equivalent stress of the inner FRP plate subjected to gravity is distributed in a W shape, the hoop stress, and the axial stress of the FRPCTs are distributed in a U shape, and the radial stress of the inner FRP plate is distributed in an I shape. The maximum displacement occurs in the middle of the FRPCTs, and the bonding between the FRP plate and the concrete is better. Finally, a calculation formula for the variation in the regularity of the tc is developed with different D, and design and construction suggestions for FRPCTs are given, which can provide technical support for the application of the FRPCTs in practical engineering.

Workability and Compressive Strength Properties of (Fly Ash-Metakaolin) based Flowable Geopolymer Mortar

RPC (Reactive Powder Concrete) is a high-strength concrete with outstanding technical qualities. One of the most crucial critical criteria in RPC development is the cement content. Cement production is seen as an environmentally unsustainable process. As a result, it is necessary to substitute cement in RPC manufacturing with an environmentally acceptable binder. Geopolymer seems to be a novel binder that can completely replace cement. The properties of constituents and their percentages in the mix significantly affect the behavior of geopolymer concrete or mortar. This research aims to produce Geopolymer RPC (GRPC) and verify the impact of the ratios of fly ash/pozzolanic materials (FA/P), sand/pozzolanic materials(S/P), finer sand/fine aggregate (S2/S1), and alkaline solution/pozzolanic materials (A/P) on its mechanical and durability properties. The results of the current works demonstrate that increase in alkaline solution to binder ratio increase the compressive strength of the mortars from 62.28 to 70.01 MPa at 62.50% to 100% alkaline/binder ratio, respectively. As well as, vfor the same alkaline/binder ratio the workability subsequently improves from 15 to 17.3mm.