scholarly journals EXPERIMENTAL INVESTIGATION ON LWC WITH COMPLETE REPLACEMENT OF COURSE AGGREGATE BY EPS BEADS

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Natalija Bede ◽  
Neira Torić Malić
Keyword(s):  
Experimental Investigation ◽  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
Expanded Polystyrene ◽  
Hardened Concrete ◽  
Test Results ◽  
Mixture Proportioning ◽  
Complete Replacement ◽  
Total Replacement ◽  
Mix Proportion

In this paper, expanded polystyrene (EPS) lightweight concrete (LWC) was investigated. The mainaim was to design EPS LWC with the specified density of 1200 kg/m3 according to standard concretemix proportion. Mix proportion included total replacement of the conventional coarse aggregate bymaximum possible amount of EPS beads, which ensures concrete workability and prescribeddensity. The results demonstrated that exactly defined mixture-proportioning and casting procedureare required to achieve designed density. For designed EPS LWC mixture properties of freshlymixedconcrete and hardened concrete were analyzed. Based on test results it is concluded thatdesigned EPS LWC can be used for structural-insulating purpose such as floors and roofs.

Effect of confinement on the behaviour of high-strength lightweight concrete columns

1986 ◽  
Vol 13 (6) ◽  
pp. 741-751 ◽  
Author(s):  
R. Basset ◽  
S. M. Uzumeri
Keyword(s):  
Experimental Investigation ◽  
Lightweight Concrete ◽  
Concrete Strength ◽  
Lightweight Aggregate ◽  
High Strength ◽  
Concrete Columns ◽  
Lightweight Aggregate Concrete ◽  
Test Results ◽  
Aggregate Concrete ◽  
Concrete Confinement

This paper summarizes an experimental investigation into the behaviour of high strength sand – lightweight concrete columns confined with rectangular ties. Fifteen reinforced and three unreinforced specimens were tested under monotonically increasing axial compression. Variables considered in this study were the longitudinal steel distribution and tie configuration, the tie steel spacing, the amount of tie steel, and the amount of longitudinal steel.The results indicated that unconfined high-strength lightweight aggregate concrete is a brittle material. The addition of lateral confining steel significantly improved the behaviour of this material, with a large amount of lateral steel resulting in very ductile behaviour. The tie configuration and resulting distribution of longitudinal steel contributed significantly to the confinement of concrete, with well-distributed steel resulting in improved behaviour. The ratio of specimen to cylinder concrete strength was observed to be 0.98, which is much higher than the commonly assumed value of 0.85.The test results were compared with results from selected theoretical confinement models. Based on the results of this investigation, existing models for concrete confinement give unconservative results for high-strength lightweight aggregate concrete and overestimate the ductility that can be achieved with this material. Key words: columns, confinement, ductility, high-strength concretes, lightweight aggregate concretes, reinforcement, stress–strain relationships, tests, ties, toughness.

Effect of Mixing Steel Dust and Shred-Like Steel Fibres on the Properties of Concrete

2019 ◽  
Vol 7 (1) ◽  
pp. 24-29
Author(s):  
A. Ajwad ◽  
N. Khadim ◽  
Abdullah ◽  
U. Ilyas ◽  
M. U. Rashid ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Coarse Aggregate ◽  
Strength Test ◽  
Hardened Concrete ◽  
Normal Concrete ◽  
Steel Fibres ◽  
Coarse Aggregates ◽  
Mix Proportion ◽  
Steel Dust

In this research, fine and coarse aggregates present in the concrete are replaced with steel dust and shred-like steel fibres, respectively in different ratios and its effect on the properties of concrete is studied. Eight batches of concrete were mixed, each with the mix proportion of 1:2:4 and water cement ratio of 0.52. Batch A was of normal concrete. In batches B, C, and D, 5%, 10%, and 15% of sand was replaced with steel dust. In batches, E, F, and G, 2%, 5%, and 8% of coarse aggregate were replaced with steel fibres. In the last batch H, both 5% of sand and 5% of coarse aggregate were replaced with steel fine and steel fibres respectively. British as well as American standards were followed during the research. Slump test was performed in a fresh state of each mix to find the effect of these replacements on workability. 12 cubes of 150mm x 150mm x 150mm for compressive strength test and 12 cylinders of 150mm diameter and 300mm height of each, for tensile strength test were made for each batch to check these strength after 3, 7, 14, 28 days. It was found that the workability of fresh concrete decreases while density of fresh as well as hardened concrete increases with these replacements. It also results in an increase in initial compressive strength and a decrease in final compressive strength as compared to those of normal concrete. As far as tensile strength is concerned an increase in initial as well as final strength was observed.

scholarly journals THE EFFECT OF CONCRETE COMPOSITION AND AGGREGATES PROPERTIES ON PERFORMANCE OF CONCRETE

2009 ◽  
Vol 15 (3) ◽  
pp. 317-324 ◽  
Author(s):  
Romualdas Mačiulaitis ◽  
Marija Vaičienė ◽  
Ramunė Žurauskienė
Keyword(s):  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
Raw Materials ◽  
Optimal Solution ◽  
Concrete Mixture ◽  
Hardened Concrete ◽  
Exothermic Effect ◽  
Concrete Composition ◽  
Binding Material ◽  
Selection Of

The properties of the hardened concrete depend on the selected raw materials: size and amount of the particles of coarse aggregate, as well as on the ratio of other components. Particular countries use various methodologies for the selection of concrete composition to select the components of the concrete mixture. However, the properties of the concrete, selected by using any methodology for the selection of the concrete composition and hardened by following the defined conditions, must satisfy the values of certain necessary characteristics. The results of the implemented research indicate that the most optimal solution is to use the coarse aggregate of multi‐fractional or discontinuous fractional composition. The optimal composition of the concrete must be selected to ensure that the binding material is not overdosed. Yet, all components must be selected in such a way, that the required properties of the final product are retained after concrete mixture hardens. When catalyst waste materials from the reactor of the catalytic cracking (15%) are used for the lightweight concrete, the density of the expanded‐clay lightweight concrete investigated and compressive strength increases even for the higher water/cement ratio, more heat is dissipated during the hydration of the cement and this exothermic effect occurs several hours earlier. Santrauka Sukietėjusio betono savybės priklauso nuo betonui parinktų žaliavų: stambaus užpildo dalelių dydžio ir jų kiekio, taip pat nuo kitų sudedamųjų dalių santykio. Betono mišinio sudedamąsias dalis šalys parenka įvairiais betono sudėties parinkimo metodais, tačiau pagal bet kurį betono sudėties parinkimo metodą parinkto ir pagal nustatytas sąlygas sukietinto betono savybės turi tenkinti tam tikrų būtinųjų charakteristikų vertes. Darbe atliktų tyrimų rezultatai parodė, kad optimaliu naudoti daugiafrakcį arba trūkiosios frakcinės sudėties stambųjį užpildą. Betono sudėtis turi būti parinkta nepereikvojant rišamosios medžiagos, tačiau visas sudedamąsias dalis parenkant taip, kad, sukietėjus betono mišiniui, išliktų reikiamos galutinio produkto savybės. Lengviesiems betonams naudojant katalizatoriaus atlieką iš katalitinio krekingo reaktoriaus (15 %), padidėja tiriamojo keramzitbetonio tankis, gniuždomasis stipris net esant didesniam V/C santykiui, o hidratuojantis cementui, išsiskiria daugiau šilumos, ir šis egzoterminis efektas įvyksta keliomis valandomis anksčiau.

scholarly journals Mixture Proportion Design Method of Steel Fiber Reinforced Recycled Coarse Aggregate Concrete

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 375 ◽  
Author(s):  
Danying Gao ◽  
Lijuan Zhang ◽  
Michelle Nokken ◽  
Jun Zhao
Keyword(s):  
Coarse Aggregate ◽  
Steel Fiber ◽  
Design Method ◽  
Target Strength ◽  
Test Results ◽  
Fiber Reinforced ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate ◽  
Mix Proportion ◽  
Fiber Characteristic

Steel fiber reinforced recycled coarse aggregate concrete (SFRCAC) is an impact minimisation building material. Mixture proportion design method of SFRCAC is developed in this paper to obtain concrete with target strength and workability, which can be used in structural members. Four key parameters of mixture proportioning, steel fiber content, water-cement ratio, water content and sand ratio are discussed through the mixture design tests. The formula for calculating the four key parameters of mixture proportions for SFRCAC are established through the statistical analysis of test results, which mainly consider the influences of recycled coarse aggregate (RCA) replacement ratio and steel fiber characteristic coefficient. The detailed procedure by using the new mixture proportion design method is illustrated with examples. The formulas established have the simple form, reflect the properties of RCA and steel fibers, enhance the mixture proportion design accuracy, and provide the reference for the mix proportion design of SFRCAC.

scholarly journals Usefulness of porphyry and amphibolites as a component of concrete for airfield pavements

2018 ◽  
Vol 163 ◽  
pp. 07002
Author(s):  
Małgorzata Linek ◽  
Piotr Nita ◽  
Paweł Wolka ◽  
Wojciech Żebrowski
Keyword(s):  
Bulk Density ◽  
Internal Structure ◽  
Coarse Aggregate ◽  
Cement Matrix ◽  
Physical Parameters ◽  
Hardened Concrete ◽  
Test Results ◽  
Laboratory Test Results ◽  
The Matrix

Coarse aggregate used as part of cement concrete is of primary significance for the obtained parameters of hardened concrete. In case of concretes intended for airfield pavements, the application of granite grit is recommended. Alternative to this type of aggregate in the form of porphyry and amphibolites aggregate was suggested. In order to assess the suitability of different aggregate types for concrete mixes, their bulk density, absorbability, polishing resistance, abrasion and crushing resistance were determined. Also, the internal structure of the suggested aggregates and its influence on changes of hardened concrete composite structure were subject to the assessment. The influence of aggregate type on the structure of cement matrix and contact areas between the matrix and aggregate grains were specified. The observed changes, in case of the internal structure of concretes based on porphyry and amphibolites aggregates, with reference to granite aggregate, resulted in changes of mechanical and physical parameters. Analyses included the determination of bulk density, absorbability, compression, bending and splitting resistance. According to the obtained laboratory test results, the significant influence of the aggregate type applied to the mix on parameters of hardened concrete, with regard to the application thereof to the airfield pavements was proved.

scholarly journals Recovery and Incorporation of expanded polystyrene SolidWaste in Lightweight Concrete

Ingeniería ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 237-249
Author(s):  
María Paula Espinoza-Merchán ◽  
Laura Juliana Torres-Parra ◽  
Nicolas Rojas-Arias ◽  
Pablo Miguel Coha-Vesga
Keyword(s):  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
Expanded Polystyrene ◽  
Raw Material ◽  
Low Density ◽  
Chemical Attack ◽  
High Consumption ◽  
Chemical Agents ◽  
Concrete Failure ◽  
Attack Process

Context: The high consumption of parts made from expanded polystyrene (EPS) generates environmental problems when disposed. Due to its low density and the low possibility of being utilized in other applications after its disposal, it is necessary to generate an alternative for the recovery and application of this type of waste. This work aims to generate an alternative in the application of EPS waste, particularly as a coarse aggregate in the manufacturing of lightweight concrete. Method: This study used discarded EPS containers as raw material. The material was cleaned, crushed and subsequently reduced in volume by applying acetone, generating pieces of polystyrene (R-PS) to be applied as a coarse aggregate for the manufacturing of lightweight concrete in different proportions. In addition, the pieces were subjected to a chemical attack process in order to observe their behavior. Results: The results show the degree of volume reduction of the EPS pieces by using different acetone ratios, establishing the best degree of reduction (in volume) of this material. Likewise, chemical attack tests show the behavior of R-PS against different agents in R-PS samples. Meanwhile, the failure tests on different concrete samples determine the best R-PS ratio as coarse aggregate for the manufacturing of lightweight concrete. Conclusions: The data obtained in this study show that the application of acetone on EPSW samples reduces its volume by up to 55 %. Concrete failure tests show that an optimum P-RS addition value, to be used as an aggregate in the manufacturing of lightweight concrete, is 7 %. This improves its resistance to chemical agents and weight reduction without significantly reducing the mechanical properties of concrete.

scholarly journals Effect of Plastic Synthetic Aggregate in the Production of Lightweight Concrete

2014 ◽  
Vol 2 (1) ◽  
pp. 83-88
Author(s):  
ELIVS M. MBADIKE ◽  
EZEOKPUBE G.C.
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
Research Work ◽  
Control Test ◽  
Cement Ratio ◽  
Coarse Aggregates ◽  
Mix Proportion ◽  
Strength Tests ◽  
Average Compressive Strength

In this research work, the effect of plastic synthetic aggregate in the production of lightweight concrete was studied. The plastic synthetic aggregate was used to replace 0-40% of coarse aggregates. A mix proportion of 1:1.8:3.7 with water cement ratio of 0.47 were used. Concrete cubes of 150mmx150mmx150mm of coarse aggregate/plastic synthetic aggregate were cast and cured at 3,7,28,60 and 90 days respectively. At the end of each hydration period, the three concrete cubes for each hydration period were crushed and their average compressive strength recorded. A total of ninety (90) concrete cubes were cast. The result of the compressive strength tests for 5-40% replacement of coarse aggregates with plastic synthetic aggregate ranges from 8.07-36.71N/mm2 as against 24.58-41.21N/mm2 for the control test. The workability for 5-40% replacement of coarse aggregates with plastic synthetic aggregate ranges from 12-61mm as against 8mm for the control test (0% replacement).

scholarly journals Guiding Paving Block Porous for Blind People

2020 ◽  
Vol 11 (1) ◽  
pp. 79-86
Author(s):  
Muhammad Isradi ◽  
Acep Hidayat ◽  
Joewono Prasetijo
Keyword(s):  
Water Absorption ◽  
Simple Form ◽  
Manufacturing Process ◽  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
Blind People ◽  
Test Results ◽  
Porous Concrete ◽  
Fine Aggregates ◽  
Road Surfaces

AbstractPorous 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.

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