High-performance Concrete Composites Research Articles

Utilization of marble waste as fine aggregate in the composition of high performance concrete containing mineral additions

This study investigates the effect of adding marble waste as fine aggregate on the properties of high-performance concrete. To achieve this objective, 10%, 20%, 30%, and 40% of marble waste fine aggregate were substituted for ordinary fine aggregate in the composition of high-performance concrete mixtures containing silica fume and ground blast furnace slag. The fresh properties were studied using slump, fresh density and air content tests, while the hardened properties were assessed using compressive and flexural strengths, ultrasonic pulse velocity, water absorption, and chemical acid attack tests. The results obtained revealed that the addition of marble waste fine aggregate significantly improved the properties of high-performance concrete and increased its resistance to chemical acid attacks. The composition-based ground blast furnace slag containing 40% marble waste fine aggregate outperformed all other compositions, increasing compressive strength by 30.98%.

Internal curing capacity of recycled coarse aggregates incorporated in concretes with low water/cement ratios

This study was performed using recycled aggregates from two concrete sources, building and civil engineering concretes, whose compositions were fully controlled.Natural aggregates are completely replaced by pre-wetted coarse concretes aggregates in the composition of high-performance concrete (HPC) in order to enhance the internal curing phenomenon governed by the self-drying of the cement paste.Comparison of the mechanical performance and microstructural analysis of these second generation concretes revealed a secondary hydration of the cement paste by a mechanism of desorption of the water absorbed in the recycled coarse aggregate, a process of “internal curing”.These water transfers were characterized both on a global and local scale around recycled aggregates incorporated in C60 and C80 concretes. The water transfer capacity is optimal in C60 concrete paste (W/C = 0.33). The decrease in permeability and water porosity of the new paste is significant for these concretes compared to the control concretes based on natural aggregates.

Optimization of high performance concrete composites by using nano materials

Optimization of high performance concrete composites by using nano materials

Effect of Fibers on Strength and Elastic Properties of Bagasse Ash Blended HPC Composites

Abstract This article presents the details of an experimental investigation carried out on test specimens to assess the effect of the addition of steel, polypropylene fibers, and hybrid fibers (steel and polypropylene) at a total fiber volume fraction of 1.0 % by volume of concrete on the workability and strength-related properties of high performance concrete (HPC) utilizing bagasse ash. All the fiber-reinforced high performance concrete composites contained 10 % bagasse ash to replace cement. The results of the experimental study show that the addition of bagasse ash enhances the mechanical properties of conventional concrete. The incorporation of steel and polypropylene fibers improved the mechanical properties of bagasse blended HPC at each volume fraction considered in this study. Subsequently, it was observed that the addition of 0.75 % steel and 0.45 % polypropylene fibers significantly improved the strength of concrete. The various combinations of steel and polypropylene fibers are investigated, and among these, the best performance was attained by a mixture that contained 0.85 % steel and 0.15 % polypropylene fiber.

Forecasting of strength and durability properties of High Performance Composites by Artificial Neural Networks (ANN)

High Performance Concrete (HPC) is the high quality concrete that requires special conformity and performance requirements. The objective of this study was to investigate the possibilities of adapting neural expert system like Artificial Neural Network (ANN) in the development of simulator and intelligent system and to predict durability and strength of HPC composites. This soft computing methods emulates the decision-making ability of a human expert benefits both the construction industry and the research community. These new methods, if properly utilized, have the potential to increase speed, service life, efficiency, consistency, minimizes errors, saves time and cost which would otherwise be squandered using the conventional approaches.

Prediction of strength and durability properties of HPC composites using Adaptive Neuro-fuzzy Inference System

High-Performance Concrete (HPC) is a high-quality concrete that requires special conformity and performance requirements. The objective of this study was to investigate the possibilities of adapting neural expert systems like Adaptive Neuro-Fuzzy Inference System (ANFIS) in the development of a simulator and intelligent system and to predict durability and strength of HPC composites. These soft computing methods emulate the decision-making ability of human expert benefits both the construction industry and the research community. These new methods, if properly utilized, have the potential to increase speed, service life, efficiency, consistency, minimizes errors, saves time and cost which would otherwise be squandered using the conventional approaches.

Effect of Aggregates on the Technological and Mechanical Properties of Glass and Basalt Fibres Reinforced Concrete

Reinforcement of high performance concrete (HPC) with glass and basalt fibres is becoming more widely used due to their high mechanical properties, sustainable manufacturing process and wide range of application in architectural and urban design. Properties of HPC composites are mainly determined by matrix composition, fibre type, volume and distribution in the concrete matrix. Granulometry and shape of aggregates has a major impact on the technological properties of concrete mix, such as water bleeding and slump size. Current study is focused on investigation of HPC reinforced by glass and basalt fibres with aggregates of different types. Quartz sand and crushed granite were used as aggregates. Two matrix compositions were used, both having proportion 1:1 of ordinary Portland cement (OPC) and total amount of aggregate. In the first case, the whole aggregate was quartz sand, and for the second it was 50% quartz sand and 50% crushed granite. For matrix reinforcement, 3% of alkali resistant glass fibres and 1.5% chopped basalt from total weight of dry materials were used. 1% from cement mass of polycarboxylate ether-based superplasticizer was used to increase workability of concrete mix. The consistency of mixtures decreased, but flexural strength increased approximately by 13% when 50% of quartz sand was replaced with crushed granite for concrete with both types of fibres.

A new mixture design methodology based on the Packing Density Theory for high performance concrete in bridge engineering

In this study, a new mixture design methodology based on the 4-parameters compressible packing model (CPM) of Packing Density Theory was proposed to satisfy the specific performance criteria of high performance concrete for prestressed concrete bridge construction. Iterative algorithms were developed to determine the parameter of critical cavity size ratio x0 which reflect the crushed aggregate particles shape property and optimize the proportions of aggregates with different size range. After the optimization of aggregates, all the components in concrete were calculated. Thirty-one concrete mixtures with coarse aggregate from 5 different sources have been formulated according to this method to validate it both in fresh and hardened state. The workability, mechanical, and durability properties are verified during the slump, compressive strength, shrinkage, chloride-penetration resistance, and freeze-thaw resistance tests to characterize the obtained high-performance concrete. It is clear from the study that the proposed method is a successful theory for optimizing composition of high performance concrete.

Time Progress of Compressive Strength of High Performance Concrete

Development in the field of concrete engineering is increasingly focused on the practical application of high performance concrete (HPC) or ultra-high performance concrete (UHPC) in construction practise. Newly developed kings of concrete are newly using in transport and building structures. The process of hydration of hydraulic binders based on Portland cement doesn ́t stop after 28 days, when the test of compressive strength take place, but it ́s a long time process that takes for many months. For design we use the values of strength of 28 days. This paper explorers how does the long-term development of compressive strength of HPC runs. The composition of HPC is significantly different from the common concrete lower strength classes. The question of the influence of additives, filler on microsilica based, silica flour to the time development of compressive strength is being explored in this paper. There is also recorded the influence of curing condition of the test specimens to the compressive strength. The age of testing samples starts at a very early ages 1, 3, 7, 21, 28, 45, 90 and 180 days. The strength in uniaxial compression was measured on cubes with dimension 100 mm.

Effect of Fly Ash on Durability of High Performance Concrete Composites

A parametric experimental study has been conducted to investigate the effect of fly ash on the durability of the concrete composites. Four different fly ash contents (10, 15, 20 and 25% respectively) were used. The durability of concrete composites includes water impermeability, dry shrinkage property, the carbonation resistance and the freeze-thaw resistance. The results indicate that the addition of fly ash has greatly improved the water impermeability and restricted the dry shrinkage of concrete composites. With the increase of fly ash content, the length of water permeability and the dry shrinkage strain of the specimens have a tendency of decrease with the increase of fly ash content. However, the addition of fly ash has a little adverse effect on the carbonation resistance and freeze-thaw resistance of concrete composites. With the increase of fly ash content, the carbonation depth is increasing and the relative dynamic elastic modulus of the freeze-thaw specimen is decreasing gradually.

HPC Composites Formulated to Counteract Early ASR Expansion

AbstractThe authors investigated the ability of different high-performance concrete (HPC) composites to restrain an alkali-silica reaction (ASR) in the presence of reactive aggregates. They evaluated the effectiveness of different binary and ternary blended cementitious systems comprising optimized contents of pulverized fly ash (PFA) and silica fume (SF) in suppressing ASR expansion. They assessed different mortar mixtures made of different contents of PFA (up to 40%) and SF (up to 15%) with water-to-binder (W/B) ratios of 0.27 for ASR expansion according to standard procedures for accelerated mortar bar test. The results showed a given pessimal combination among the ternary mixtures in which there was an obvious synergistic interaction where ASR expansion was at its minimum level.

Durability of high performance concrete composites containing silica fume

A parametric experimental study has been conducted to investigate the effect of silica fume on the durability of the concrete composites. Four different silica fume contents (3%, 6%, 9% and 12%) were used. The durability of concrete composites includes water impermeability, dry shrinkage property, the carbonation resistance and the freeze–thaw resistance. The results indicate that the addition of silica fume has a little adverse effect on the dry shrinkage property of concrete composites. With the increase of silica fume content, the dry shrinkage strain is increasing gradually. However, the addition of silica fume has greatly improved the water impermeability, the carbonation resistance and the freeze–thaw resistance of concrete composites. With the increase of silica fume content, the length of water permeability and the carbonation depth of the specimens are decreasing gradually, and the relative dynamic elastic modulus of the specimens has a tendency of increase with the increase of silica fume content.

Effect of polypropylene fiber on fracture properties of high-performance concrete composites

AbstractA parametric experimental study has been conducted to investigate the effect of polypropylene fiber on the workability and fracture properties of high-performance concrete (HPC) composites containing fly ash and silica fume, with the five fiber volume fractions (0.04%, 0.06%, 0.08%, 0.1%, and 0.12%) used. The results indicate that the addition of polypropylene fiber decreases the workability of the HPC composites containing fly ash and silica fume. With the increase in the fiber volume fraction, both of the slump and the slump flow decrease gradually. Furthermore, the addition of polypropylene fiber has greatly improved the fracture parameters of concrete composite containing 15% fly ash and 6% silica fume, such as fracture toughness, fracture energy, effective crack length, maximum midspan deflection, the critical crack opening displacement, and the maximum crack opening displacement of the three-point bending beam specimens. When the fiber volume fraction increases from 0% to 0.12%, the fracture parameters increase gradually. The variation rules of the fracture parameters indicate that the capability of the polypropylene fiber to resist the crack propagation of the concrete composite containing 15% fly ash and 6% silica fume is becoming stronger and stronger with the increase in fiber volume fraction with the fiber volume fraction not above 0.12%.

HPC Strength Prediction Using Artificial Neural Network

An artificial neural network of the fuzzy-ARTMAP type was applied for predicting strength properties of high-performance concrete (HPC) mixes. Composition of HPC was assumed simplified, as a mixture of six components (cement, silica, superplasticizer, water, fine aggregate, and coarse aggregate). The 28-day compressive strength value was considered as the only aim of the prediction. Data on about 340 mixes were taken from various recent publications. The system was trained based on 200 training pairs chosen randomly from the data set, and then tested using remaining 140 examples. A significant enough correlation between the actual strength values and the values predicted by the neural network was observed. Obtained results suggest that the problem of concrete properties prediction can be effectively modeled in a neural system, in spite of data complexity, incompleteness, and incoherence. It is demonstrated that the approach can be used in multicriterial search for optimal concrete mixes.