scholarly journals Lightweight Reactive Powder Concrete Containing Expanded Perlite

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3341
Author(s):  
Stefania Grzeszczyk ◽  
Grzegorz Janus
Keyword(s):  
Water Absorption ◽  
Lightweight Concrete ◽  
Mixing Time ◽  
Lightweight Aggregate ◽  
Test Results ◽  
Expanded Perlite ◽  
Quartz Powder ◽  
Density Reduction ◽  
Concrete Mix ◽  
Reactive Powder

This paper presents the test results of the lightweight concrete properties obtained by adding expanded perlite (EP) to an RPC mix in quantities from 30% to 60% by volume of the concrete mix. It has been shown that in these cases it is possible to obtain concrete containing 30% by volume with density of approximately 1900 kg/m3 and the compressive strength > 70 MPa, with a very low water absorption value (3.3%), equal to the water absorption value of RPC without lightweight aggregate (3.3%). However, with the increased quantity of perlite (from 45% to 60%), the concrete density reduction is not observed, as the expanded perlite demonstrates very low resistance to crushing. With the increased amount of perlite, the longer periods of mixing time for all the mix components are required to obtain the homogeneous and fluid concrete mix, what causes grounding down EP. Therefore, using larger quantities of this aggregate in RPC is not recommended. The lightweight RPC shows very good freeze-thaw resistance in the presence of de-icing salt (the scaling mass is lower than 0.1 kg/m2). The above is explained by the compact microstructure of this concrete and the RPC mix location in open pores on the perlite aggregate surface, which consequently affects the strengthening of the aggregate-matrix contact without an interfacial transition zone (ITZ) visible. It has been demonstrated that pozzolanic activity of expanded perlite is much lower than the activity of silica fume and quartz powder, and its impact on increasing the RPC strength is minimal.

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.

Surface Modification for Porous Artificial Lightweight Aggregate and Mechanical Properties of the Resulting Concrete

2011 ◽  
Vol 117-119 ◽  
pp. 1302-1305
Author(s):  
Ning Liao ◽  
Hong Zhi Cui
Keyword(s):  
Mechanical Properties ◽  
Surface Modification ◽  
Water Absorption ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
High Water ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
High Water Absorption ◽  
Change Material

This research is one part of preliminary work for integrated structural-functional energy storage concrete by using porous artificial lightweight aggregate and phase change material. Lightweight aggregate concrete (LWAC) has been applied more and more extensively in recent years, but high water absorption of porous artificial lightweight aggregate (LWA) is inconvenient for LWAC production. In order to improve LWA application, in this paper, two aspects of lightweight aggregate (LWA) study have been carried out, namely, a) LWA surface modification. The effects of different concentration of surface modifier on water absorption of modified LWA were studied. b) Mechanical properties of lightweight aggregate concrete made of the unmodified and modified LWAs Through comparing the water absorption of unmodified and modified LWAs, it can be known that the surface modification for LWA can reduce the water absorption obviously. The three kinds of lightweight concrete possess nearly same strength at 7-day and, at 28-day, the strength of LWAC using 1:20 modified LWA is highest and that of LWAC using 1:5 modified LWA is lowest. 28 days compressive strength of LWAC using 1:20 modified LWA could be up to 46.1MPa.

Strength and Freeze-Thaw Testing of Lightweight Aggregate Concretes

2013 ◽  
Vol 723 ◽  
pp. 507-514 ◽  
Author(s):  
Ming Ju Lee ◽  
Ming Gin Lee ◽  
Jing Yu Chen ◽  
Mang Tia
Keyword(s):  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Strength Development ◽  
Hydraulic Pressure ◽  
Test Results ◽  
Performance History ◽  
Normal Concrete ◽  
Freeze Thaw ◽  
Before And After ◽  
Reactive Powder

This investigation indicates the effects of freeze-thaw cycles on the strength development and durability of lightweight aggregate concretes. Two lightweight aggregate concrete, one normal concrete and one reactive powder concrete were used in this study, and total four types of concrete mix were named NC, LWC1, LWC2, and RPC. Before and after freeze-thaw test, the samples were evaluated by the compressive strength, fflexural strength, and impact abrasion tests. The test results show that steady decrease in compressive and flexural strength after freeze-thaw testing for most concrete specimens. The lightweight aggregate used in the LWC1 mix for this laboratory study had a good freeze-thaw performance history, but the LWC2 mix with lightweight aggregate approaching the 24-hour water absorption had a bad result. It might be due to the void volume required to release hydraulic pressure developed during cyclic freezing.

Research on Homogeneity of Expanded Perlite Lightweight Concrete

2014 ◽  
Vol 599 ◽  
pp. 74-77
Author(s):  
Ping Yang ◽  
Wei Xia Zhao ◽  
Jin Chao Yang ◽  
Li Liu ◽  
Mian Li Cao
Keyword(s):  
Fly Ash ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Expanded Perlite ◽  
Aggregate Concrete ◽  
Good Workability

This paper discusses the reason of segregation of expanded perlite lightweight aggregate concrete. By adding fly ash, high effective admixture, the expanded perlite pre-wetting and so on,the expanded perlite lightweight concrete,CL5-CL10,was confect with good workability, homogeneity, no bleeding and segregation, easy casting and excavation.

Time-Dependent Properties of Lightweight Concrete Using Sedimentary Lightweight Aggregate

2010 ◽  
Vol 168-170 ◽  
pp. 2235-2240
Author(s):  
How Ji Chen ◽  
Wen Po Tsai ◽  
Ming Der Yang
Keyword(s):  
Lightweight Concrete ◽  
Drying Shrinkage ◽  
Lightweight Aggregate ◽  
Normal Weight ◽  
Time Dependent ◽  
Test Results ◽  
Fine Sediments ◽  
Normal Weight Concrete ◽  
Shrinkage And Creep ◽  
Shihmen Reservoir

A kind of lightweight aggregate (LWA) has been successfully developed in Taiwan, which was made by expanding under heat fine sediments dredged from the Shihmen Reservoir. In this study the performances of concrete made from the aforementioned LWA were tested and compared with those of the companion normal weight concrete (NC). The test results show that the so produced lightweight concrete (LWAC) exhibited a comparable time-dependent properties (i.e., compressive strength, elastic modulus, drying shrinkage, and creep) as compared with those of the companion NC. Based on the results, it can be concluded that the use of prewetted LWAs and the incorporation of pozzolan materials can effectively control the drying shrinkage of LWAC. The specific creep of the LC mixture was obviously higher than that of the NC mixture at the same curing time.

scholarly journals LIGHTWEIGHT CONCRETE MAKING ANALYSIS USING MIXED CELLULOSE

2019 ◽  
Vol 2 (2) ◽  
pp. 85-91
Author(s):  
Nanang Budi Setyawan ◽  
Fredy Kurniawan
Keyword(s):  
Compressive Strength ◽  
Experimental Method ◽  
Lightweight Concrete ◽  
Mix Design ◽  
Waste Paper ◽  
Test Results ◽  
Concrete Mix Design ◽  
Concrete Mix ◽  
Recycle Paper ◽  
Compressive Strength Of Concrete

Development era of globalization has resulted in increasing number of second-hand goods / waste that its existence can be a problem for life in the future. Many things are done in order to recycle paper cement in order to overcome this problem the existence of waste. One way is to use waste paper to be a part of the building. The purpose of this study, to determine the compressive strength and optimum density. Laboratory experimental method uses a variation of 10%, 20%, 30% and testing conducted in the form of compressive strength and density. From the test results obtained by the result of decrease in the compressive strength and density. In addition cellulose concrete mix design with variations determined that 10%, 20%, 30% resulted in a decrease in the compressive strength of concrete,

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.

scholarly journals Effect of Aggregate Size on Strength Characteristics of High Strength Lightweight Concrete

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1314
Author(s):  
Hui Wei ◽  
Yang Liu ◽  
Tao Wu ◽  
Xi Liu
Keyword(s):  
Compressive Strength ◽  
Lightweight Concrete ◽  
Aggregate Size ◽  
Lightweight Aggregate ◽  
High Strength ◽  
Medium Size ◽  
Test Results ◽  
Estimation Model ◽  
Strength Tests ◽  
Single Size

Effects of aggregate size on the mechanical properties of lightweight concrete (LC) were investigated. Four gradings of lightweight aggregate (LWA) were designed and used to prepare the specimens for compressive strength, splitting tensile strength, and flexural strength tests. An estimating method for compressive strength of LC was then established. The compressive strength of tested LC was up to 95 MPa at 90-day curing time. The test results suggested that the absence of medium-size particles decreased the compaction of LC, therefore the density and compressive strength were negatively affected. Specimens having single size of aggregate showed lower splitting tensile and flexural strengths than that having three sizes of LWA. The parameters of the estimating model were determined according to the test results, and the compressive strength predictions of estimation model were compared with the results from other literature.

Evaluation of applicability of expanded shale to produce lightweight aggregate as a replacement for commercial LECA in constructions

2021 ◽  
pp. qjegh2020-176
Author(s):  
Mehdi Torabi-Kaveh ◽  
Mohammadreza Moshrefyfar ◽  
Jafar Zarezadeh ◽  
Seyed Mohammad Ali Moosavizadeh
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Lightweight Concrete ◽  
Construction Materials ◽  
Physical And Mechanical Properties ◽  
Lightweight Aggregate ◽  
Mineralogical Composition ◽  
Lightweight Aggregates ◽  
Porous Microstructure ◽  
Expanded Shale

This study examined the potential of some shales obtained from different formations in Yazd province to produce Lightweight aggregates (LWAs) as natural materials and without the application of additives. Before heating the samples, the materials' usefulness for producing lightweight aggregates was examined by detecting the elemental and mineralogical composition of the shale samples. The presence of aluminosilicates and flux content confirmed and met the required conditions discussed by Riley's theory for the bloating process. Among the studied shale samples, Kharanagh shale samples of Kh1 and Kh2 were found as the most suitable materials to produce highly porous, light and mechanically durable aggregates after heating at the optimum temperature of 1200°C for a heating duration of 10min. The produced LWAs showed low density (for sample Kh1 equal to 0.7gr/cm3 which is close to the commercial LECA), low water absorption (quick water absorption indices of 5.35% and 5.48% for samples Kh1 and Kh2, respectively, which are less than one-third of LECA water absorption), porous microstructure (porous like LECA but with smaller pore size), and good mechanical properties (with aggregate impact and aggregate crushing values less than that of LECA and in the range of values suggested for construction aims). Finally, it was revealed that the produced LWAs have suitable microstructure, physical and mechanical properties, comparable with the commercial ones, which approve their potential for use as construction materials in lightweight concrete and road surface constructions.

Characteristics of Cold-Bonded Lightweight Aggregate Produced with Different Mineral Admixtures

2012 ◽  
Vol 174-177 ◽  
pp. 978-983 ◽  
Author(s):  
Le Anh Tuan Bui ◽  
Chao Lung Hwang ◽  
Chun Tsun Chen ◽  
Meng Ying Hsieh
Keyword(s):  
Water Absorption ◽  
High Performance ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Mineral Admixtures ◽  
Unit Weight ◽  
Crushing Strength

Cold bonded lightweight aggregate (LWA) was produced by adding 0%, 25% and 50% granulated blast furnace slag (GGBS) or rice husk ash (RHA) to fly ash (FA) by the pelletization process with cement additives. The results show that GGBS addition significantly improved the crushing strength of LWA, whereas there was no effective on crushing strength of LWA when RHA was used. GGBS addition significantly reduced the water absorption of LWA; on the contrary, effect of RHA was to increase the water absorption. Unit weight of LWA added RHA was in range of 719-903 kg/m3, while that of LWA added GGBS was in range of 918-1082 kg/m3. High performance lightweight concrete (LWC) made with the selected LWA (60% FA + 40% Cement and 30% FA + 40%Cement + 30%RHA) had unit weight lower than 2000 kg/m3. The 28-day compressive strength of the LWC was in range of 49 to 57 MPa. The results of the electrical resistivity and ultrasonic pulse velocity tests indicate that the LWCs might be considered to be durable concrete.

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