Use Of Fine Aggregates Research Articles

Experimental investigation on no fines concrete by addition of natural fibres

No fines concrete is a type of lightweight concrete that is made without the use of fine aggregates. In this experimental investigation, the effect of adding bamboo and sugarcane fibres on the mechanical properties of no fines concrete was studied. The specimens were prepared by replacing a portion of the coarse aggregates with 1.5% of bamboo and sugarcane fibres by volume. The specimens were tested for compressive strength and splitting tensile strength at 7, 14, and 28 days of curing. The results showed that the addition of bamboo and sugarcane fibres improved the mechanical properties of no fines concrete. The optimal percentage of fibre content was found to be 1.5% by volume, which improved the compressive strength and splitting tensile strength by 23% and 18% respectively, compared to the control specimens. Additionally, the use o natural fibres in no-fine concrete can result in a more sustainable and eco-friendly construction material.

Central composite design application in the optimization of the effect of waste foundry sand on concrete properties using RSM

The abundance of waste foundry sand (WFS) produced by the foundry industry has become a global issue. As a result, foundry waste management and disposal are getting more complex, necessitating more extensive and inventive efforts. The purpose of this study was to use WFS as a partial replacement to reduce the use of fine aggregate in various concrete mixtures and to evaluate fresh concrete performance such as slump and mechanical properties such as compressive strength (CS), split tensile strength (STS), and flexural strength (FS). WFS was adjusted using the Design-Expert software's Central Composite Design (CCD) tool in Response Surface Methodology (RSM). The optimization process investigated the interaction between WFS ratio and curing days on the mechanical properties of concrete. The responses of the optimization process were the CS, STS, and FS, which were generated by the quadratic regression model created by ANOVA. The WFS was replaced in 10% increments from 0% to 40%. The highest mechanical properties were achieved at 20% replacement and 56 days of curing with a CS of 29.37 MPa, STS of 3.828 MPa, and FS of 8.0 MPa. The quadratic model was suggested for the three responses by RSM, in which the coefficient of determination (R2) ranges from 0.987 to 0.995, showing the model's high significance. Up to a 30% replacement level, the fresh qualities of all substitutes were nearly identical to the control mix. So, 20% replacement is the optimum replacement level, and 30% is the general replacement level. As a result, it can be inferred that WFS can replace 20% of natural fine aggregate in order to obtain normal concrete strength. In contrast, for non-structural concrete, WFS can replace 30% of natural sand, which improves environmental sustainability.

A Study on Durability for Rigid Pavement Against Acid Environment and Displacement Model

An acidic environment commonly found in peat soils or expansive soil will harm the quality of rigid pavement by considering its use at long-life plan, traffic load, and minimization of damage to the crossroad due to vehicle braking. As a concrete provider, chemical admixture as mixed materials today is widely used with the reasons of workability, initial strength, as well as saving of material used. This research aimed to find out the durability of concrete admixture using sika-NN and plastocrete (retarding and water reducing admixture) at the acid environment and knowing the displacement that occurred using ABAQUS software modeling. It used the laboratory experimental method and the cube concrete sample 15×15×15 cm with the compressive strength of 33.2 MPa. A total of 18 concrete samples were immersed using normal pH water and H2SO4 at pH 1 ± 1 tested at 3, 7, 14, 28, 60, and 90 days using the Duplo method. In this research, the concrete durability was carried out using, Ultrasonic Pulse Velocity Test (UPVT) to test the density, compressive test, and modeling concrete displacement on peat soils with vehicle loads in acidic environments using software ABAQUS. The mixed design results show an average setting time value of about 112 minutes. Coarse aggregate and cement decrease due to additives is approximately 24% and 18% respectively, increasing the use of fine aggregate to 16.49%, but the value of concrete density increases base on soaking time. Besides that, there is a decrease in compressive strength up to 16% at the age of 90 days. The value of displacement in the modelled pavement uses a maximum load of 8 tons each 2.994 mm for concrete with normal water and 3.045 mm for concrete with an acid environment respectively. Concrete soaked in acid water is the greatest deformation that occurred in rigid pavement using ABAQUS and indicates that acid water has an impact on decreasing concrete quality.

Influence of Ash and Coconut Shell Against Compressive Strength and Permeability Characteristics of Pervious Concrete

Pervious concrete or non-fine concrete is a simple form of lightweight concrete made by eliminating the use of fine aggregates. As a result of not using fine aggregate in pervious concrete, then created a cavity filled with air and water can be passed. This cavity resulted in reduced density of the concrete as well as the reduced amount of area that needs to be covered by cement paste, thereby reducing the compressive strength. To increase the compressive strength of pervious concrete, in this study will utilize waste material. The waste material is the cocnut shell ash and coconut shell to strengthen the coarse aggregate bonds, so it is expected to increase the compressive strength along with the increase in permeability. Thus, in this study will replace part of the coarse aggregate with coconut shell with percentage 0%, 2,5%, 5%, 7,5%, 10% and partially replace cement with coconut shell ash with percentage 0%, 2,5%, 5%, 7,5%

Investigating properties of pervious concretes containing coconut shell flake and ash

Pervious concrete or non-fine concrete is a simple form of lightweight concrete made by eliminating the use of fine aggregates. As a result of not using a fine aggregate in pervious concrete, then created a cavity filled with air and water can be passed. This cavity resulted in a reduced density of the concrete and the reduced amount of area that needs to be covered by a cement paste, thereby reducing the compressive strength. This study aimed to utilize waste material to increase the compressive strength of pervious concrete. The waste material was the coconut shell ash and coconut shell flake. The method was to strengthen the coarse aggregate concrete mixture. It was expected to increase the compressive strength along with the increase in permeability. Thus, in this study, the researchers will replace part of the coarse aggregate with coconut shell flake with percentage 0%, 2,5%, 5%, 7,5%, 10% and partially replace cement with coconut shell ash with percentage 0%, 2,5%, 5%, 7,5%. The results show that the combination of coconut shell flake and coconut shell ash does not increase the compressive strength of the concrete mixture. However, it increases the porosity, permeability, and as a result, the density is getting lower. Further study will be performed on porous concrete using coconut shell flake for lower load facilities, such as pedestrian or bicycle pathways.

Compressive Strength, Permeability and Porosity Analysis of Pervious Concrete by Variation of Aggregate and Compacting Method

Pervious concrete is one of the innovation from conventional concrete which has interconnected void, thus enabling it to drain water. Compared to conventional concrete, pervious concrete has different physical and mechanical characteristics, but composed by the same material which is Ordinary Portland Cement (OPC), coarse aggregate, water, fine aggregate, and admixture. The use of fine aggregate in pervious concrete mixture is limited due to the fine aggregate can block the interconnected pores thus lowering the permeable ability of the pervious concrete. The objective of this research is to analyze the characteristics of the pervious concrete which is compressive strength, permeability, and porosity with variation of aggregate and compacting method. The pervious concrete mixture consists of 15%, 20%, and 25% of fine aggregate variations and standard rodding, proctor Hammer, and concrete vibrator as the compacting methods used. The amount of cement used on each mixture is 360 kg/m3, w/c = 0.3, and admixture as much as 2.8% of the cement used. The slump, compressive strength, and porosity test is based on ASTM Standard, while the permeability test is based on ACI Standard. The maximum compressive strength test result is 13.103 N/mm2 achieved by the mixture with 25% fine aggregates and compacted using concrete vibrator. The permeability test result ranged from 0.053 cm/s to 1.192 cm/s, and porosity ranged from 2.261% to 41.083%.

Micromechanical modelling of pervious concrete reinforced with treated fibres

Pervious concrete has been widely used in parking lots and airport fields. However, excessive cracking and spalling issues of pervious concrete remain a challenge for its adoption in wider applications, since its binding material proportion is low and the use of fine aggregates is nearly zero. When loaded in compression, failure appears first in the weak concrete zone, induced by the random distribution of voids. The process continues until failure of the whole specimen. Fibre-reinforcement delays crack generation and enhances the strength of the host matrix. However, the bonding mechanism between the fibre and concrete matrix is a controversy in the literature. In this study, the influence of polypropylene fibre inclusion on the strength and stiffness of pervious concrete microstructure was studied through delicate interface modelling. Two-dimensional microstructures of pervious concrete were generated using Matlab and Ansys parametric design languages. A cohesive-zone technique was then used to model the interface between fibres and the concrete matrix. Load–displacement plots were thus obtained in Ansys for specimens under compression for various void–fibre percentages and different treated interface properties.

Guiding Paving Block Porous for Blind People

Abstract Porous concrete is a simple form of lightweight concrete made by eliminating the use of fine aggregates (sand). That is a mixture of cement, water and coarse aggregate. Use of the guiding paving block porous for blind people is one of the efforts that will be made to overcome the inundation due to water spills from sufficiently high rainfall, providing comfort and safety for users so as not to slip easily due to slippery road surfaces, that will be used must have a measurable value of permeability and porosity to optimize the function of using porous concrete. Guiding paving block porous for blind people are very economical and have a great advantage in absorbing water so the surface is always dry, and can reduce accidents due to slippery roads. Another advantage is that the product is environmentally friendly with handmade, designed using a mixture of plastic bottle waste material can be made apart from the manufacturing process in various shapes and various colors. From the test results it has a strength of 10-15 mpa in the precast age of 28 days with a water absorption capability of up to 10L / m2.

Self-Compacting Concrete with Recycled Coarse Aggregate and Manufactured Sand

This article mainly focused on the influence of recycle coarse aggregate and manufactured sand on the properties of self compacting concrete (SCC). The main purpose of this research is reuse of recycled aggregate in SCC and also to reduce use of fine aggregate by replacing manufactured sand. The SCC mixtures were prepared with 0, 25, 50, 75 and 100% replacement of recycle coarse aggregate in natural coarse aggregate and M-Sand in fine aggregate with a Water/Binder ratio of 0.36. Different test covering fresh properties of these SCC mixtures were executed the results were compared with EFNARC guidelines and IS 10262:2019. The feasibility of utilizing recycled aggregate and M-Sand in self compacting concrete has been examined and found that it is suitable for concrete.

Limbah Beton Sebagai Material Agregat Halus Terhadap Kuat Tekan Karakteristik

Concrete waste from building construction can cause problems for the environment [1]. The use of fine aggregates from concrete waste can be a solution. The purpose of this study is to determine the value of aggregate characteristics and the value of concrete compressive strength from the utilization of concrete waste as substitution fine aggregate use the DOE (department of environment) method and referring to standards SNI. This study used 50% and 60% waste mortal substitution on sand. The results showed that the characteristics of fine aggregate and coarse aggregate met the characteristic requirements for fineness modulus sand of 2.65 (Zone 2) while the aggregate was roughly 6.44 (Zone 3). The value of compressive strength with 50% and 60% concrete waste substitution each obtained the value of characteristic compressive strength of 57.24 kg / cm² and 101.03 kg / cm². The value of using mortar waste as fine aggregate substitution gives a positive value to the quality of concrete. This is evidenced increase in the value of 14.89% in concrete waste substitution 60%.

Study of properties and strength of no-fines concrete

Nowadays, special concrete is widely adopted in construction industry. No-fines concrete is a one of the special concrete which eliminate the use of fine aggregates in concrete mixing. The application of no-fines concrete has been introduced to construction industry especially pavement construction. Due to its high porosity behavior, the relative density of no-fines concrete is lower than normal concrete of 2400kg/m3 which also helps in reducing dead weight in the design. In term of strength, no-fines concrete also gave lower compressive strength compared to normal conventional concrete. The aggregate/cement ratio also found to be a factor affecting its strength as it is depending on the interlocking or the strength of bonding between aggregate and cement. Also, concrete with varies mix ratio gives different has been studied for its physical and mechanical properties. In addition, there are further study of introducing fiber materials to determine the chance of enhancement in no-fines concrete study. By elimination of fines aggregates, the development and application of no-fines concrete in the construction industry will be more economical than normal concrete. This paper reviews and studies the performance characteristics and strength of no fine concrete based on previous researcher’s outcome.

PENGARUH SUBSTITUSI AGREGAT HALUS SABANG TERHADAP KINERJA LASTON LAPIS AUS (AC-WC)

Asphalt and Aggregate is the main ingredient of the asphalt concrete layer which determines the quality of asphalt pavement. One of the main cause of the damage and decrease of asphalt pavement strength on the road is the low strength and durability of the asphalt mixture. . But in the other side the utilization of local materials is expected to be used maximally to improve efficiency in terms of financing, especially for island area such as Sabang city of Aceh Province. Importing material from Ace Besar district is need a big cost. In solving this problem therefore it is necessary to maximize the use of local material. this research is done for find out the effect of the use of fine aggregate on the characteristics of the coarse layer of asphalt concrete mixture characteristics (AC-WC)with the addition of Sabang fine aggregate starting from 0%, 25%, 50%, 75% and 100%. The initial step in this research is find the value of optimum asphalt content (KAO).The result of this research shows that the more composition of the Sabang fine aggregate then the decreasing the stability value. The highest stability value is on the asphalt concrete mixture without Sabang fine aggregate substitution with the asphalt content is 5,38% with the amount of 1.658,73 kg and the lowest stability value is on the asphalt concrete mixture with 100% of Sabang fine aggregate substitution with asphalt content is 6,35% in the amount of 979,35 kg. The maximum composition of sabang fine aggregate which pass the requirement specification of Asphalt concrete AC-WC volumetric characteristic is 50% on the level of 5,87% with the stability value is 1.225,81 kg.

Lightweight concrete of continuous structure without fine aggregate

The study deals with basic properties and area of application of lightweight concrete of continuous structure without fine aggregate. When fine aggregate is excluded from the concrete structure, it becomes lightweight, has lower thermal conductivity and cost, simpler production technology. It also has durability sufficient for wall panels, water resistance, frost resistance and a number of other indicators. The paper describes additives used for concrete air entrainment. Using these additives does not complicate the production technology of panels, the panels can be easily transported and have sufficient stability and durability upon storage. The article justifies effective application of light concrete with continuous structure without fine aggregate in low-rise construction. Light concretes of continuous structure without fine aggregate allow to completely exclude the use of fine aggregate, to sharply reduce density and thermal conductivity of concrete, as well as to reduce moisture content and humidity of products, improve their cohesion and workability and get a number of other benefits. The study shows that light concrete without fine aggregate numerous advantages prove that it will be used in construction practice for a long time.

Analisis Kuat Tekan Beton yang Menggunakan Pasir Laut sebagai Agregat Halus pada Beberapa Quarry di Kabupaten Fakfak

SNI 03-6861-1-2002, states that the fine aggregate used in concrete structures should use river sand. However, the use of fine aggregate in Fakfak regency in general is still dependent on sea sand potential is quite large. The purpose of this study were: 1) determine the characteristics of sea sand in Fakfak regency as a component of the concrete mix; 2) determine the strength of concrete resulting from the use of sea sand. This research is an experimental research laboratory by means of sample testing and analysis of the characteristics of aggregates and concrete compressive test using a compression test machine. Results of testing the characteristics of fine aggregate to quarry in Fakfak regency consisting of quarry Kampung Seberang, quarry Kampung Sungai, quarry Tanjung Wagom and coarse aggregate from the quarry Kayuni can generally be used for a mixture of concrete for eligible characteristics of concrete aggregate but fine aggregate (sand) it is best to Tanjung Wagom quarry because of the fineness modulus 2.93 and included in zone 2. Compressive strength characteristics resulting from the quarry Kampung Seberang 122.84 kg/cm2 quarry Kampung Sungai 129.59 kg/cm2 and quarry Kampung Tanjung Wagom 144.27 kg/cm2 of the planned concrete quality 250 kg/cm2 or down 50.86% , quarry Kampung Sungai 48.16% and quarry Tanjung Wagom 42.29% down or strength is only reached at quarry Kampung Seberang 49.14%, quarry Kampung Sungai 51.84% and quarry Tanjung Wagom down 57.71%

South African construction and demolition waste procedure and its sourced material effects on concrete

This paper presents the results of a study into the use of fine aggregate from construction and demolition waste (C&DW) in the South African construction industry, and the impact this has on the important fresh and hardened properties of concrete when used as partial replacement for virgin materials. The C&DW were tested at replacement levels of 0%, 25%, 50%, 75% and 100%. The recycled fine aggregate was pre-soaked to mitigate the expected effect of higher water absorption of recycled concrete aggregate (RCA). However, pre-soaking of the fines attributed to the poor performance of the fresh and hardened properties of the concrete. The pre-soaking procedure used was problematic when used with fine aggregates and caused a large amount of excess water to be added to the concrete mix as a result. This study highlights the importance of planning the demolition process of a structure to ensure that the best possible quality of RCA can be extracted. The study revealed that the use of recycled fine aggregate as a replacement of virgin materials in the manufacture of concrete has a much greater negative impact than the use of coarse recycled aggregates. In addition, the pre-soaking procedure of fine aggregates warrants special attention.

Characterization of pervious concrete through image based micromechanical modeling

Pervious concrete has been widely used in parking lots and airport fields. However, past experience has shown durability and strength of the pervious concrete remains a challenge for adopting them in wider applications, as the binding material proportion is low and the use of fine aggregates is nearly zero. When loading in compression, the failure appears first in the weak concrete zone induced by the random distribution of voids. The process continues until the failure of the whole specimen occurs. Thus, the position, size and shape distribution of voids in the pervious concrete microstructure control the overall behavior of the material. In this work, the influence of the distribution of voids on the strength, stiffness, and permeability of pervious concrete microstructure is studied by 2D image analysis and finite element modeling. The position and size distribution of the microstructure voids are first summarized through Fast Fourier Transformation (FFT) analysis. A finite element analysis is then conducted on the microstructure models regenerated through the derived microstructure characteristics using ANSYS Parametric Design Language (APDL). The effect of the sample size of 2D microstructures is studied by varying the section size and a possible representative volume element (RVE) is therefore found. Predicted stress-strain plots are generated for the 2D specimen under compressive load and the obtained results, including stiffness, strength and permeability are compared with the results from the experiments conducted following ASTM standards. The comparison between models and physical experiments showed around or above 90% accuracy, which validates the suggested micromechanical analysis method of the previous concrete composite.

Study on concrete using waste materials by partial replacement of aggregates to reduce global warming gases

The climate change due to global warming is one of the greatest environmental issues we face now. The green house gases including CO2 are released during cement and steel manufacturing process. In order to reduce the amount of green house gases, an attempt has been made to reuse the waste materials along with concrete in construction industries. In recent years, attempts have been made to increase the utilization of fly ash, quarry dust, granite and construction and demolition debris to partially replace the use of fine aggregate and coarse aggregate in concrete are gathering momentum. This paper presents information on fly ash, granite and quarry dust based concrete, material and the mixture proportions, the manufacturing process, and the influence of various parameters on the properties of fresh and hardened concrete with plain concrete and partial replacement of fine aggregate by flyash and quarry dust and coarse aggregate by granite and C & D debris concrete. The column specimens were tested under axial compression to investigate the effects of waste materials. Since the materials used were locally available waste materials, a detailed characterization was planned. In this paper, an attempt was made to utilize the waste materials by effectively recycling and filling in steel tubular circular columns with recycled aggregate concrete instead of conventional concrete. An empirical equation for calculating the design load carrying capacity of the composite column was developed using the experimental results. The test results were compared with the international codes and new theoretical models were suggested for the design. In this paper, experimental and analytical investigations were carried out to study the strength and behaviour of CFST columns over the entire range of loading. The ultimate loads and behaviour of CFST were compared with those of the hollow steel tube columns. From these elaborative experimental and analytical investigations that were done, it is concluded that out of all the waste materials used, the contribution of C & D debris and quarry dust are significant. The remaining materials that include fly-ash and granite are reasonably contributed in the performance enhancement under axial loading conditions. Finally, it is concluded that materials recovered from various waste stream are suitable to be used as secondary aggregates in concrete. The advantage of using such waste materials provides generally a low cost construction than using virgin aggregates and the elimination of the need for waste disposal in landfills. Utilization of these waste materials in concrete leads to an effective solid waste management technique and will also be cost effective. The exploitation of available natural resources and raw materials required for the construction industries can also be reduced which in turn reduces the release of green house gases which causes global warming. Keywords: Fly-ash, recycled aggregate concrete, granite, waste management, global warming.

Investigation on Estimation Method for Water Content of Fresh Concrete Using Scattering-Type Neutron Moisture Meter

In order to assure high accuracy in estimation of water content of fresh concrete by the neutron moisture meter, the establishment of a suitable calibration curve is the most important. In this study, fine aggregate containing the required amount of water in a container with fixed capacity is measured with the scattering-type neutron moisture meter. And the calibration curve is obtained from the relationship between the measured neutron counting and the amount of water added to fine aggregate. The kind of fine aggregate hardly influences the neutron counting. The neutron counting becomes large with the increase of particle size of fine aggregate, even when added water amount is the same. However, use of fine aggregate not less than 2.50 in fineness modulus dose not noticeably affect the neutron counting. The method with calibration curve using fine aggregate can evaluate the water content of fresh concrete with a good accuracy.

Resistance of Steep Concrete Block Pavements to High-Velocity Water Flow

In some locations, the use of concrete block pavement (CBP) involves the combination of a very steep and storm-sensitive region with the consequent risk of high-velocity water flow on pavements. Under these conditions, and because of the special characteristics of CBP and its unknown response to high-velocity water flow, two problems must be addressed: ( a) the danger of sand erosion from the bedding layer and the joints between the blocks, because of surface drainage and water flow, and ( b) the danger of development of uplift forces from the downward water seepage. The cumulative effect of these two dangers may cause a gradual loss of support of the CBP, leading to total failure. CBP was tested under high-velocity water flow on a one-to-one scale, with definition of flow and failure mechanisms in the CBP and with the adoption of proper solutions. Five tests were performed in an experimental water flume, differing in type of bedding. Use of conventional sand bedding under continuous water-flow conditions was found to be inappropriate. Such bedding cannot provide the necessary stability for the CBP. However, the use of fine aggregate as bedding material ensured the stability of the CBP under continuous supercritical flow velocities and steep channel slopes. Excellent performance of the CBP was observed with the underlying fine aggregate bedding. The use of sufficiently coarse aggregate as bedding material is the proper engineering solution for preventing erosion and ensuring the absolute stability of a CBP under high water-flow velocities under supercritical conditions.