Plain Cement Concrete Research Articles

Effect of Aluminium Fiber on the Strength property of Concrete

This experimental work is aimed at determining the influence of aluminium waste fiber on plain cement concrete. To achieve this aim, compressive strength test has been conducted. The compressive strength test has been conducted in Compression machine. The plain cement concrete with the ratio 1:1.5:3 at 0.55 water cement ratio has been utilized in this study. Aluminium waste has been used as additional material in concrete. The weight of aluminium has been taken from 0.5%, 1.5% and 1.5% by weight of cement of varying aspect ratios that are 2.5 (length=0.5 inch, width=5mm), 5 (length=1inch, width=5mm) and 7.5 (1.5 inch, 0.5mm). A total number of ten batches, each batch contained six cubes and were casted for evaluation of compressive strength test. The curing ages selected for this particular study have been 7 and 28 days. It has been observed in this study that aluminium waste has resulted into a decrease in compressive strength of concrete as compared to normal concrete. This study has made application of solid waste as addition material in concrete. Therefore, this study will be helpful to reduce environmental pollution.

Use of in-situ tests like flat plate dilatometer (DMT) andSeismic Dilatometer (SDMT) vis-à-vis finite element-based software to examine the efficacy of ground improvement work at a high rise residential project in Kolkata

ABSTRACT Rapid urbanization in India, particularly in Kolkata, has led to a scarcity of suitable land, necessitating effective ground improvement techniques. A case study was evaluated using 500mm diameter, 10m long plain cement concrete (PCC) piles installed at 2m c/c spacing to enhance subsoil for a high-rise residential structure. Initial Dilatometer (DMT) tests showed the subsoil was unsuitable for shallow foundations. Post-PCC piling, DMT tests revealed a 30-40% improvement in subsoil stiffness. The factor of Safety against liquefaction was calculated using DEEPSOIL software. Further analyses with DMT Settlement software and PLAXIS 2D confirmed that post-piling, the raft foundation settlement remained within permissible limits, proving the effectiveness of the ground improvement measures.

Performance Study of Plain Cement Concrete Containing Quartz Powder and Eggshell Powder as Partial Replacement of Cement

Concrete remains a mainstay among construction materials despite ongoing improvements to enhance its environmental friendliness and effectiveness. This study explores the effects of adding quartz and eggshell powder to concrete. The experimental investigation measures concrete samples’ compressive strength, split tensile strength, and flexural strength at 7, 28, and 90 days. Concrete mixes with varying percentages of quartz powder and eggshell powder and their combinations were prepared and tested. The findings show that using quartz and eggshell powder improves the strength characteristics of concrete, with several mixtures performing better than conventional concrete. The examination of experimental data highlights the potential of these supplementary materials to enhance the sustainability and durability of concrete structures. It provides valuable insights into the mechanisms contributing to the strength improvement. These results advance the field of construction materials by contributing to ongoing efforts to create high-performance, environmentally friendly concrete compositions.

Experimental Study On Mechanical Behaviour Of Human Hair Reinforced Concrete

Fibre-reinforced concrete offers a practical and cost-effective solution for addressing micro-cracks and similar structural weaknesses in concrete. Traditional concrete is inherently weak in tension, necessitating measures to enhance its performance in this regard. One unconventional yet promising option for reinforcement is human hair due to its impressive tensile strength. Human hair fibres (HF) are readily available, affordable, and do not degrade quickly, which can contribute to environmental concerns. This study aims to investigate the impact of incorporating human hair fibres into plain cement concrete, with a focus on enhancing compressive strength, tensile strength, flexural strength, and crack prevention while promoting economic and eco-friendly concrete practices.
 Prior to incorporating human hair fibres into the concrete mix, a meticulous cleaning process involving acetone is carried out. Experimental assessments were conducted on concrete beams, cubes, and cylinders, utilizing various proportions of human hair fibres (0%, 1%, 1.5%, and 2% by weight of cement). The findings reveal that the introduction of human hair fibres as reinforcement leads to a noteworthy enhancement in concrete performance. Specifically, with a 2% inclusion of human hair fibres, we observed a 3.29% upsurge in compressive strength, a 10.87% increase in tensile strength, and a 12.69% improvement in flexural strength in comparison to traditional concrete.

Mechanical performance of fiber-reinforced concrete and functionally graded concrete with natural and recycled aggregates

This study aims to assess the mechanical performance of functionally graded concrete (FGC) in comparison to conventional plain cement concrete (PCC) and fibre-reinforced concrete (FRC). For this purpose, five concrete mixes were prepared, defined in eleven patterns, including PCC as a control mix, two FRC mixes, and eight combinations for FGC mixes. The hooked-end steel fibres and recycled thin polyethylene terephthalate (PET) strips from used bottles were utilized as fibres in 0.75 % of the volume of the mix in the FRC and FGC mixes. The natural aggregates were replaced by 15 % by weight with recycled plastic aggregates (RPA) and recycled concrete aggregates (RCA) in the FGC mixes. The mechanical performance of all specimens was assessed by compressive, split tensile and flexural strength tests, whereas the concrete quality was evaluated by the ultrasonic pulse velocity (UPV) test. The results revealed that the FRC mix containing steel fibres has 50.6 % higher compressive strength, while PET-FRC exhibited 42.4 % lower strength than the PCC. The best combination of the FGC mix is RCA + SFRC (H), which showed 27.6 % more compressive strength than PCC. The steel fibre-reinforced concrete (SFRC) mix has the highest split tensile strength, which is 47.5 % higher than the PCC. The best combination of FGC mixes is SFRC + PET-FRC (J), yielding 29.3 % higher tensile strength than PCC. On the other hand, both fibres contribute to the flexural strength enhancement of FRC. The FGC mix (K) yielded the highest flexural strength, with PET-FRC and SFRC in the upper and bottom layers, respectively, giving 40 % more flexural strength than the PCC specimen. The UPV values depicted that fibres and recycled aggregates in FGC specimens enhanced the quality of concrete. The highest value of UPV was recorded in the mix PCC + SFRC (G) containing PCC and steel fibres, which almost reached the upper limit of the recommended UPV values.

Investigations on mechanical and durability properties for pavement quality concrete using hybrid fibres

Hybrid fiber reinforced concrete was used to develop pavement quality concrete (PQC) to overcome the disadvantages associated with rigid pavements prepared with plain cement concrete. Hooked-end steel (ST) fiber of 60 mm in length and polypropylene (PP) fiber with a length of 36 mm were used as reinforcement for the hybrid fiber concrete mix. The proportion of ST and PP fibers used was upto 1% with which PP fibers varied from 0 to 0.45% at a 0.15% increment in the total mix. This study aims to assess the various strength workability and durability issues of the concrete mixes. Significant improvement in the properties of mechanical and durability characteristics was observed in the results with the addition of these fibers as compared to control cement concrete. Among all the mix proportions, the overall performance of the mixture by adding steel fiber at 0.85% and polypropylene fiber at 0.15% contents was found to be the best. However, a slight increase in water absorption value was observed by the incorporation of fibers into concrete due to increased thickness in the transition zone and porosity.

Destructive and Non-Destructive Analysis of Polypropylene Fibre Reinforced Concrete

Plain Cement Concrete (PCC) is brittle and has low tensile strength. The brittleness can be avoided by adding fibre. Fibre-reinforced concrete (FRC) is concrete containing fibrous material spread across concrete, which increases its structural integrity. Addition of fibres to concrete makes it an isotropic material and converts its brittle behaviour to ductile behaviour. In the Fibre Reinforced Concrete, polypropylene fibres are rationally combined to produce a cementitious composite that derives benefits from each of the individual fibres and exhibits a synergistic response. Based on I.S. Code method of mix design, proportion of different ingredients was obtained to get M30 grade concrete. Samples were prepared with varying the volume fraction of fibres from 0.50% to 2.50%. The optimum dosage is determined from among the above mixes. The result shows that optimum dosage is obtained at 1.50% addition of fibre. The main aim of the present experimental investigation was to use different volume fractions of polypropylene fibres to produce FRC and thus to evaluate its performance by comparing Destructive tests such as compression, tension, flexure and Non-destructive tests such as Rebound Hammer, Ultrasonic Pulse Velocity and Durability Parameters such as Water Absorption, Sorpitivity etc., .From the results obtained fibre reinforced concrete shows higher values than normal concrete under Compression, Split Tensile and Flexural Strength. The water absorption is reduced for FRC compared to Normal Concrete.

Application of fiber reinforced cement composites in rigid pavements: A review

Concrete that has been reinforced with fibers has more structural integrity. It has uniformly distributed, short discrete fibers that are randomly orientated. The volume of fibers, the aspect ratio of the fibers, and other variables all have an impact on the flexural strength of FRC. In this essay, each of the criteria is covered. Carbon dioxide pollution in the atmosphere is attributed to cement manufacture. According to studies, producing one ton of cement results in the release of nearly half a ton of CO2 into the environment. In order to lower carbon footprints and create sustainable pavements, the cement content must be decreased. Due to the enormous design thickness required by conventional plain cement concrete, it is necessary to increase the flexural strength of concrete to reduce pavement thickness. Concrete's flexural strength is increased by the addition of fibers, and pavement design thickness is decreased. Cement use and CO2 emissions will decrease with a reduced design thickness. As a result, the application of FRC can significantly lower the carbon emissions of pavement per unit area linked to the manufacture of materials. Calculations of the cost of paving per unit area reveal that Glass Fibers, Polypropylene Fibers, and Hooked Steel Fibers are more cost-effective reinforcement options. The paper reviews the academic literature on fiber-reinforced concrete through a methodical literature study A keywords analysis is done to find out the most focused fiber. This study describes several fiber kinds and their impact on the mechanical characteristics of concrete. The characteristics of steel, plastic, synthetic, recycled, and natural fibers are widely covered in this essay. A comparative examination of several fiber kinds at various replacement percentages is carried out. The economic and environmental advantages of FRC in rigid pavements are discussed.

Relative experimental evaluation of properties of concrete with addition of super – Plasticizers

The second most – widely used man – made material worldwide is considered to be as Concrete. Concrete is a simple construction material, produced with four basic ingredients: Cement, Fine Aggregates, Coarse Aggregates and Water. But, with the need of modification on the properties of concrete under different circumstances and various application areas, admixtures were also added while making the concrete mix. As per the latest codal provisions of IS 10262: 2019, admixtures had been added as a core ingredient, along with the four basic ingredients of concrete mix, for the determination of the quantity of each ingredient in making a concrete batch of desirable grade. With more technological advancements in the industry of cement and concrete, researchers, academicians and engineers are in a constant trend in trying to modify the properties of concrete by using various additives (such as chemical admixtures) in order to develop specialized concretes, which enhances the strength of the concrete along with the workability of concrete, thereby increasing the lifespan of the concrete – made structure. This study gives a general idea of how the different doses of chemical admixture alters the various properties of both fresh concrete and hardened concrete, such as workability and strength of concrete in compression, tension and flexure. The laboratory experiments were conducted for the determination of the characteristics of the concrete in both fresh and hardened state as per the procedures laid in Indian Standard Codal Provisions. Different dosages of chemical admixture used varies from 0% to 3% and comparable results were obtained with plain cement concrete, having 3 batch of M 20 grade concrete, each batch were tested with number of samples for getting an average value of workability and compressive strength, tensile strength and flexural strength. The result with 2% addition of admixture shows the optimum results.

Investigations on GUJCON-CRF Nylon 6 fiber based cement concrete for pavement

Plain concrete has very low tensile strength, limited ductility, and poor resistance to cracking. Due to its poor tensile strength and cracking propagation, concrete eventually leads to brittle failure on the application of heavy loads. Hence, fiber reinforcement is used to improve the physical properties of plain cement concrete. This study aims to investigate the behavior of concrete when GUJCON-CRF Nylon 6 fibers are incorporated in varying quantities as secondary reinforcement in cement concrete to alter its brittle nature and reduce plastic shrinkage cracking. The fresh characteristics (slump cone test and compaction factor test), mechanical characteristics (compressive strength test and flexural strength test), and durability characteristics (abrasion test, sulfate attack test, acid attack test, and water permeability test) of concrete were investigated experimentally in this study using a superplasticizer (Structuro 202), based on polycarboxylic technology and GUJCON-CRF Nylon 6 fiber. In this study, GUJCON-CRF Nylon 6 fiber was included in concrete in amounts of 0.2 %, 0.25 %, 0.30 %, 0.35 %, and 0.40 % by cement weight, maintaining a consistent water-to-cement ratio of 0.38. An M40-grade concrete mix design was prepared for our exploration and testing. The concrete specimens (cubes and beams) prepared from each type of mix were tested at 7 days and 28 days, respectively, to study the mechanical properties of hardened concrete. The test results of all specimens were analyzed, and it was observed that the mix with 0.25 % replacement of the weight of cement provided the most competitive concrete mix. Compared to ordinary concrete, the compressive and flexure strength increased by 16.8 % and 36.59 %, respectively. It was discovered that abrasion resistance increased significantly up to 0.30 % replacement, then it became insignificant. A minimum value of permeability and water absorption was also reported for 0.25 % of cement weight replacement by GUJCON fiber.

Numerical Analysis of Double-Leaf Composite Stiffened Door Subjected to Blast Loading

Doors are the most critical part in any structure as they may eventually fail first when subjected to extreme loads such as blasts. Blast resistant doors in a structure work as effective barriers against blast pressure thus making the entire structure safe. Accordingly, the need to provide blast resistant doors arises in important structures to endure blast pressure. Herein, the comparative performance of a three-hinged five-latched double leaf composite door subjected to blast loading is investigated using finite element analysis software LsDyna. The composite door consists of front and rear steel plates composed of armor steel and three different infill materials, i.e., polyurethane (PU) foam, aluminum syntactic foam with 200 μm cenosphere (Al200), or plain cement concrete (PC) are explored in this investigation. Comparative studies of these composite doors are performed by varying the thicknesses and types of infill material and blast-scaled distances. The peak deflection, permanent deflection, internal energy, and total energy are compared among the doors considered herein. Weight and cost analysis of the door are also considered to determine the most cost-effective solution. The numerical results show that the polyurethane core door illustrates better performance for 150 mm of core material. However, the plain concrete infill door and cenosphere aluminum alloy core door demonstrate enhanced performance for 100 mm core thickness at 0.15, 0.2, 0.3, and 0.4 m/kg1/3 scaled distances.

Study on Comparision of Life Cycle Cost Between White Topping and Btiuminuos Overlays

Abstract: The focus of the present study is on construction of long-lasting and better performing pavements. Usually, with respect to the rehabilitation of the pavement, the construction agencies go with the bituminous overlays as their first priority without considering the condition of the existing pavement structure. But the advantages of cement concrete (CC) pavements that have proved to perform better and are considered to be long-lasting must be explored. The use of Thin White Topping (TWT), and Ultra-Thin White Topping (UTWT) pavements is currently gaining popularity in the area of pavement construction.. And hence it is the era where the Thin and Ultra-Thin White Topping methods are gaining their popularity. The present study provides details on the approaches adopted in measuring the performance of TWT and UTWT pavement surfaces built of plain cement concrete, cement in cement concrete replaced by 50% ground granulated blast furnace slag, cement in cement concrete replaced by an admixture called Conplast NC, and 50% of cement in cement concrete replaced by GGBS and Conplast NC. The study also includes comparison of strength of composite beams of various thicknesses when subjected to repeated wheel loads under Modified Immersion Wheel Tracking Equipment when supported by a 50mm thick bituminous layer below. The performance results on the tests on the specimens of 150mm thick admixture-added CC beam and the 100mm thick GGBS-cumAdmixture-added CC beam were almost the same. This indicated that the thickness of cement concrete slabs could be reduced by 50mm by replacing 50% of cement in cement concrete with GGBS-cum Admixture-added CC beam. Based on the study on cement concrete, and composite beams, and the study of life cycle costs, it was observed that a road surface with cement concrete overlay would be more appropriate when compared to a bituminous concrete (BC) overlay. Together, these findings suggest that the concrete overlay acts as the most economic method.

Experimental studies on confined compressive strength of Stainless Steel Wire Mesh (SSWM) wrapped concrete columns

The findings of an experimental evaluation of the axial compressive strength of an M25 grade Plain Cement Concrete (PCC) column confined with locally available Stainless Steel Wire Mesh (SSWM) are presented in this paper. Various types of Fiber Reinforced Polymer (FRP) are usually employed to strengthen the load-bearing components of concrete structures. However, these FRP materials exhibits brittle failure and debonding of FRP strip or wrap. Stainless Steel Wire Mesh (SSWM), on the other hand, is a cost-effective substitute for FRP materials when it comes to strengthening of structural elements. In this study, effectiveness of SSWM for confinement of concrete columns is demonstrated through experimental study. For the research, column specimens with a diameter of 150 mm and a height of 300 mm are used. Test specimens are strengthened with one-layer circumferential wrap of SSWM. Three variants of SSWM i.e. SSWM 30 × 32, SSWM 40 × 32 and SSWM 50 × 34 are considered for the study. After 28 days of moist curing, SSWM is applied to the column surface using epoxy SIKADUR 30LP. Axial compressive load-carrying capacities of strengthened specimen are compared with that of control specimens. From the comparative study it is found that SSWM 40 × 32 performs better compared to other variants of SSWM considered for this study. Compared to the control specimen, the load-carrying capacity of the column strengthened with SSWM 40 × 32 is increased by 29.35%. For all the specimen, failure patterns are observed in addition to the load–displacement and stress–strain behaviour. Results of present experimental investigation establishes the suitability of SSWM for confinement or strengthening of concrete elements subjected to compression.

Fresh and hardened state properties of waste tire fiber and steel fiber reinforced concrete

Concrete is a widely used construction material but is known that several properties of plain cement concrete can be improved by the addition of certain fibers in certain percentages and this procedure-oriented substance is known as Fiber-reinforced concrete (FRC). And one of such most commonly used fibers is steel fiber, which is known to improve the mechanical properties of concrete. The usage of the waste tire as fibers would reduce the environmental degradation and it is also proven that it too can improve the properties of PCC. This paper investigates certain fresh and hardened state properties namely workability, compressive strength, and abrasion resistance of concrete reinforced with both steel and tire fibers in various proportions of the volume of concrete at 0%, 0.25%, 0.75%, 1%, and the results were analyzed.

Study on Microwave Deicing Efficiency of Microwave-Absorbing Concrete Pavements and Its Influencing Factors.

Microwave deicing technology, as a new environmentally friendly deicing technology, can effectively solve the problem of the frequent icing of road surfaces in the winter, which affects the safety of traffic. To improve the efficiency of microwave deicing on cement concrete pavement, this study proposed the use of magnetite, iron sulfide slag, steel slag, lead-zinc slag, and graphite as microwave-absorbing materials, and conducted microwave deicing tests under the influence of five factors, namely the form of the pavement surface structure, the content of the microwave-absorbing material, microwave power, the shielding state, and dry and wet conditions. Layer by layer, we selected the combination of pavement surface structure, microwave-absorbing material content, microwave power, shielding state, and dry and wet conditions on the bottom surface of the concrete slab with the optimal deicing effect. The results showed that the 2 cm scattered microwave-absorbing surface concrete structure has the fastest heating rate; the higher the magnetite content and microwave power, the higher the deicing efficiency; the maximum heating rate can be increased by 17.6% when the shielding layer is set at the bottom of the cement concrete slab; and the heating rate of the microwave-absorbing concrete slab in the wet state is increased by 20.8% relative to the dry state. In summary, 7000 W of power, a magnetite content of 60 vol % in the scattered microwave-absorbing surface, a shielding layer set at the bottom surface, and wet conditions can greatly improve the efficiency of microwave deicing compared with the microwave ice melting effects of plain cement concrete and other microwave-absorbing materials mixed into the concrete. In addition, the temperature uniformity of the microwave-absorbing materials is essential to improve the deicing efficiency of microwave-absorbing concrete, so it is essential to explore it further.

Development of Low Calcium Fly-Ash Based Geopolymer Concrete Using Marble Powder

If you compare geopolymer concrete to cement concrete, it is a novel and rising trend in today's concrete business. It can be used as a good substitute for cement concrete and has a variety of benefits over cement concrete, including greater durability. Geopolymer concrete is a kind of green concrete that was created by repurposing waste materials from various power generation companies and thermal power plants. Because of the presence of alkaline activators in geopolymer concrete, it has strong heat resistance capabilities and provides firm bonding between particles, which may result in superior mechanical properties. Geopolymer concrete is also more durable than plain cement concrete. When exposed to acids in a maritime environment, it demonstrates exceptional resistance to corrosion. When low calcium fly ash is used in place of cement, the strength is increased to 40 N/mm2. The amount of marble powder used as a filler was varied as a percent of 0, 5, 10, 15, 20, and 25% to achieve the desired strength of 40 N/mm2. The highest strength was observed when fly-ash was used as a 20% replacement for cement.The molarity of NaOH was employed as 12 molarity at a 2.5 alkaline liquid ratio, which is a good value. They were kept consistent throughout all of the mixes.

Comparison between the Influence of Finely Ground Phosphorous Slag and Fly Ash on Frost Resistance, Pore Structures and Fractal Features of Hydraulic Concrete

Hydraulic concrete in cold regions is necessary for good frost resistance. The utilization of finely ground PS (FGPS) in the construction of hydropower projects could solve the pollution issue and the fly ash shortage problem. In this work, the influence of FGPS and fly ash on frost resistance, pore structure and fractal features of hydraulic concretes was investigated and compared. The main results are: (1) The inclusion of 15–45% FGPS reduced the compressive strength of plain cement concretes by about 21–52%, 7–23% and 0.4–8.2% at 3, 28 and 180 days, respectively. (2) The inclusion of FGPS less than 30% contributed to the enhancement of 180-day frost resistance. At the same dosage level, the FGPS concrete presented larger compressive strengths and better frost resistance than fly ash concrete at 28 and 180 days. (3) At 3 days, both the addition of FGPS and fly ash coarsened the pore structures. FGPS has a much stronger pore refinement effect than fly ash at 28 and 180 days. The correlation between frost resistance of hydraulic concrete and pore structure is weak. (4) At 28 days, the incorporation of FGPS and fly ash weakened the air void structure of hydraulic concrete. At 180 days, the presence of FGPS and fly ash was beneficial for refining the air void structure. The optimal dosage for FGPS and fly ash in terms of 180-day air void refinement was 30% and 15%, respectively. The frost resistance of hydraulic concretes is closely correlated with the air void structure. (5) The pore surface fractal dimension (Ds) could characterize and evaluate the pore structure of hydraulic concretes, but it was poorly correlated with the frost resistance.

Numerical and analytical optimisation of functionally graded concrete incorporating steel fibres and recycled aggregate

Recent studies applied the concept of functionally graded material in fibre reinforced recycled aggregate concrete (FRRAC) to produce functionally graded concretes (FGC) with enhanced post-cracking flexural behaviour. In these studies, two-layered FGC were produced using plain cement concrete (PCC) and FRRAC in the top and bottom layers, respectively. It was found that a top layer of PCC as thin as 10% of the total height of the specimen (or h/H = 0.90) can enhance the post-cracking flexural behaviour of FGC. Based on these experimental results, this study aims to demonstrate the feasibility of using FGC in construction projects by estimating the ratio h/H that results in an optimal post-cracking flexural response of FGC beams produced with PCC and FRRAC. For this, the finite element analysis software ABAQUS, and the analytical model based on an analysis of evolutionary sections were used to estimate the flexural behaviour of homogeneous FRRAC and FGC beams considering different values of h/H. Then, the simulated results were compared with previous experimental results and the optimal h/H of FGC with FRRAC was evaluated considering its application in rigid pavements. In general, the simulated results indicate that the optimal post-cracking flexural performance is obtained for h/H between 0.80 and 0.90. Furthermore, the lowest slab thickness was achieved for h/H = 0.80.

Effect of recycled aggregate and supplementary cementitious material on mechanical properties and chloride permeability of concrete

With impending demand for sustainable development, construction wastes as recycled aggregate (RA) to produce recycled aggregate concrete (RAC) is inevitable. However, RA makes adverse effect on performance of RAC. To enhance its performance, the supplementary cementitious materials (SCM), including ground granulated blast furnace slag, red mud, and glass powder, were used to partially substitute cement. In this investigation, the plain cement concrete and mineral-admixture concrete with four replacement ratios of RA were poured. For each mixture, the compressive strength, dynamic elastic modulus, and resistivity were determined; Besides, chloride penetration test was conducted in a tidal cycling simulation device, in which specimens with dimension of 100 × 100 × 400 mm3 were used to explore the effect of drying-wetting time ratios RD/W on chloride diffusion. It was found concrete with 50% RA exhibits improved compressive strength and equivalent chloride resistance through 25% SCM addition. Concrete containing 100% RA achieves equivalent or even superior chloride resistance to control group as SCM added by 45%. With the increase of RD/W, the diffusion of chloride is more serious. Considering the inhomogeneity of concrete pores, a double-porosity transport model solution was derived based on Fick's second law. Combined with test results, a time-dependent model was then established to predict chloride concentration in concrete containing RA and SCM. Furthermore, an analytical solution of cumulative chloride content diffused into concrete was derived to quantify chloride permeability. Subsequently, a linear correlation between chloride permeability and resistivity is confirmed. This investigation will encourage the use of RA in marine engineering, thereby leading to a more sustainable and cleaner production.

Evaluation of Strength Parameters of PCC and Hybrid FRC

Abstract: The present trend in concrete technology is towards increasing the strength and durability of concrete to meet the demands of modern construction. The aim of this paper is to study the effect of hybrid fiber (steel & polypropylene) in concrete and compare its properties with that of plain cement concrete. The findings showed that the addition of hybrid fibers to plain cement concrete improved its mechanical properties.