Alkali-Activated Matrix Based on Metakaoline with Lightweight Aggregate

2013 ◽  
Vol 787 ◽  
pp. 250-255 ◽  
Author(s):  
Jaroslav Válek ◽  
Petr Novosad ◽  
Lenka Bodnárová
Keyword(s):  
Mechanical Properties ◽  
High Temperatures ◽  
Thermal Load ◽  
Lightweight Concrete ◽  
Polypropylene Fiber ◽  
Size Fraction ◽  
Fiber Reinforcement ◽  
Lightweight Aggregate ◽  
Mix Design ◽  
Alkali Activated

The paper focuses on design and verification of mix-design of lightweight concrete with alkali-activated matrix with lightweight aggregate Liapor. Alkali-activated matrix was designed on the basis of ground metakaoline and micronized limestone. Mixes of concrete with alkali-activated matrix and lightweight porous aggregate Liapor of size fraction 8 mm were designed and their rheological and physico-mechanical properties were tested. To reduce shrinkage and to increase resistance to high temperatures, dispersed polypropylene fiber reinforcement was used and testing specimens made from this concrete with alkali-activated matrix were exposed to thermal load and tested.

Mechanical Properties of Fiber Reinforced Lightweight Aggregate Concrete

2011 ◽  
Vol 477 ◽  
pp. 274-279 ◽  
Author(s):  
Yi Xu ◽  
Lin Hua Jiang ◽  
Hong Qiang Chu ◽  
Lei Chen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Water Hyacinth ◽  
Steel Fiber ◽  
Polypropylene Fiber ◽  
Lightweight Aggregate ◽  
Splitting Tensile Strength ◽  
Lightweight Aggregate Concrete ◽  
Fiber Types

In this study, the effects of fiber types on the mechanical properties of lightweight aggregate concretes were investigated. Three types of fibers, namely, polypropylene fiber, steel fiber and water hyacinth (Eichhornia crassipes) fiber, and two types of lightweight aggregates, namely, expanded polystyrene and ceramsite were used. The compressive strength and splitting tensile strength of concretes were tested. The results show that both the compressive strength and the splitting tensile strength were improved by adding a reasonable volume of steel fiber and polypropylene fiber into LWAC. The addition of water hyacinth fiber had little effect on the compressive strength of LWAC, while a little increase was observed in the splitting tensile strength.

Lightweight Aggregate Concrete as an Alternative for Dense Concrete in Post-Tensioned Concrete Slab

2018 ◽  
Vol 926 ◽  
pp. 140-145 ◽  
Author(s):  
Małgorzata Mieszczak ◽  
Lucyna Domagała
Keyword(s):  
Mechanical Properties ◽  
Lightweight Concrete ◽  
Concrete Slab ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Large Span ◽  
Shrinkage And Creep ◽  
Theoretical Results ◽  
Post Tensioned

The paper presents the results of tests conducted on two lightweight aggregate concretes made of new national Certyd artificial aggregate. This research is intended to first application of lightweight concrete to construct large-span post-tensioned slab. In addition to mechanical properties development, shrinkage and creep during 3 months of loading were tested. The obtained results are compared with theoretical results predicted by standard. Conducted tests indicated, that measured values of shrinkage and creep are significantly lower than predicted ones. This is promise for application of tested concrete in construction of post-tensioned slabs.

scholarly journals Damping Property of Cement Mortar Incorporating Damping Aggregate

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 792 ◽  
Author(s):  
Yaogang Tian ◽  
Dong Lu ◽  
Jianwei Zhou ◽  
Yuxuan Yang ◽  
Zhenjun Wang
Keyword(s):  
Mechanical Properties ◽  
Cement Mortar ◽  
Damping Ratio ◽  
Polypropylene Fiber ◽  
Lightweight Aggregate ◽  
Experimental Results ◽  
Optimal Dosage ◽  
Polymer Emulsion ◽  
Rubber Powder ◽  
Damping Property

This study proposes a new cement mortar incorporating damping aggregate (DA) and investigates the mechanical properties and damping property of the cement mortar. Four types of DA were prepared, lightweight aggregate presaturated water and three types of polymer emulsion. Further, the effects of polypropylene fiber and rubber powder on the performance of the cement mortar were studied. The experimental results showed that the damping ratio of specimens containing 70% DA was approximately three times higher than that of the reference mortar, with a slight decrease in the mechanical properties. Adding fiber was more effective than rubber powder in improving the damping ratio of the cement mortar, and the optimal dosage of fiber was 0.5%.

scholarly journals Supercritical Carbonation of Lightweight Aggregate Containing Mortar: Thermal Behavior

2014 ◽  
Vol 600 ◽  
pp. 345-356
Author(s):  
Marçal Rosas Florentino Lima Filho ◽  
Sandro Marden Torres ◽  
Leon Black ◽  
Andressa de Araújo Porto Vieira ◽  
Rodinei Medeiros Gomes ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Thermal Conductivity ◽  
Supercritical Carbon Dioxide ◽  
Thermal Behavior ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Mix Design ◽  
Lightweight Aggregates ◽  
Cylindrical Samples ◽  
Potential Use

Lightweight concrete shows good insulation properties, depending on several parameters such as mix design and aggregate type. Perlite aggregate is one of the most effective aggregates for such a purpose, mainly because of its low thermal conductivity (0.04 W/m.°C), but is not available globally. This paper explores the potential use of another source of thermal efficient aggregate, vermiculite (0.058 W/m.°C) which is available in Brazil and other countries where perlite is absent. Cylindrical samples were cast by using two lightweight aggregates, perlite and vermiculite, and treated with supercritical carbon dioxide. Supercritical carbonation (SCC) of concrete can improve mechanical, thermal and durability features. In this paper, the effect of SCC on the thermal behavior of lightweight mortars was investigated with regards to physical and microstructure features and thermal behavior due to cooling.

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.

COMPRESSIVE STRENGTH EVALUATION OF LIGHTWEIGHT CONCRETE WITH EXPANDED GLASS AGGREGATE BY ULTRASONIC PULSE VELOCITY METHOD

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Christopher Collins ◽  
Saman Hedjazi
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Normal Weight ◽  
Unit Weight ◽  
Normal Weight Concrete

In the present study, a non-destructive testing method was utilized to assess the mechanical properties of lightweight and normal-weight concrete specimens. The experiment program consisted of more than a hundred concrete specimens with the unit weight ranging from around 850 to 2250 kg/m3. Compressive strength tests were performed at the age of seven and twenty eight days. Ultrasonic Pulse Velocity (UPV) was the NDT that was implemented in this study to investigate the significance of the correlation between UPV and compressive strength of lightweight concrete specimens. Water to cement ratio (w/c), mix designs, aggregate volume, and the amount of normal weight coarse and fine aggregates replaced with lightweight aggregate, are the variables in this work. The lightweight aggregate used in this study, Poraver®, is a product of recycled glass materials. Furthermore, the validity of the current prediction methods in the literature was investigated including comparison between this study and an available expression in the literature on similar materials, for calculation of mechanical properties of lightweight concrete based on pulse velocity. It was observed that the recently developed empirical equation would better predict the compressive strength of lightweight concrete specimens in terms of the pulse velocity.

Experimental Study on Mechanical Properties of Hybrid Fiber Reinforced Full Lightweight Aggregate Concrete

2011 ◽  
Vol 197-198 ◽  
pp. 911-914 ◽  
Author(s):  
Li Yun Pan ◽  
Hao Yuan ◽  
Shun Bo Zhao
Keyword(s):  
Mechanical Properties ◽  
Apparent Density ◽  
Steel Fiber ◽  
Polypropylene Fiber ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Fiber Reinforced ◽  
Mass Content ◽  
Hybrid Fiber ◽  
Aggregate Concrete

Tests were carried out to study mechanical properties of hybrid fiber reinforced full lightweight aggregate concrete (HFRFLAC), the hybrid fiber was composed by steel fiber and polypropylene fiber, the expanded-shale and lightweight sand were used as coarse and fine aggregates. The apparent density and strengths in cubic compressive, splitting tensile and flexural tensile states of HFRFLAC were obtained. The results show that the average dry apparent density increases with the increasing cement content, which is much more affected by fraction of steel fiber by volume than mass content of polypropylene fiber; the tensile strengths increase somewhat with the increasing mass content of polypropylene fiber; all of the strengths increase with the increasing fraction of steel fiber by volume, and obvious are the enhancement of tensile strengths; there are somewhat relevance between the effects of polypropylene fiber and steel fiber on mechanical properties of HFRFLAC.

scholarly journals FLEXURAL BEHAVIOR OF REINFORCED LIGHTWEIGHT CONCRETE BEAMS MADE WITH ATTAPULGITE AND ALUMINUM WASTE

2021 ◽  
Vol 25 (02) ◽  
pp. 24-35
Author(s):  
Zahraa A. Mirza ◽  
◽  
Nibras N. Khalid ◽  
Keyword(s):  
Mechanical Properties ◽  
Failure Mode ◽  
Ultimate Load ◽  
Lightweight Concrete ◽  
Concrete Beams ◽  
Lightweight Aggregate ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Lightweight Aggregate Concrete ◽  
Flexural Ductility

Lightweight concrete reduces the total dead load of structural elements and seismic loads significantly. This paper presents the production Attapulgite Lightweight aggregate concrete (ALWAC) and its effect on the flexural behavior of reinforced concrete beams. Attapulgite was treated with sodium hypochlorite of 6% concentration for 24 hours. The variable considered was the aluminum waste (AW), used as a fiber, of fraction (0, 0.5 and 1%) by concrete volume. Behavior was investigated in terms of cracking and ultimate load, load-deflection relationship, failure mode, crack patterns and flexural ductility. The mechanical properties of the ALWAC were studied. It was observed that, Attapulgite improves the mechanical properties of concrete when comparing the experimental value with theoretical ones for the reference mixture. AW has a disparate effect on the mechanical properties of ALWAC. The increase in the proportions of AW showed an increase in the cracking load and decrease in the ultimate load by 37.14% and 22.45 %, respectively, at AW of 1%. Experimental value of ultimate load in all beams was higher than the theoretical value (ACI simplified method). AW increases the deflection at the same magnitude of applied load, and reduces the number and propagation of the flexural cracks in beams. All beams exhibited a typical tension failure mode and failed in ductile manner.

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