Study of Lightweight Concrete for Roof Insulation Materials

This paper presents an experimental study to determine the thermal transmittance of various types of lightweight concrete with an objective to assess the applicability of lightweight concrete as a roof insulation material. The lightweight concrete ranging in density from 400 kg/m3 to 1700 kg/m3 was investigated. The results were also compared with normal weight concrete. It was found that the expanded clay aggregate concrete with density of 700 to 900 kg/m3 had adequate insulation property and enough strength to be applied without the use of surface tiles. Lightweight concrete with Perlite provided better insulation than expanded clay aggregate concrete. Because of its lower in strengths, Perlite concrete required the use of surface tiles to permit maintenance access to roof.

Permeability of Lightweight Aggregate Concrete with Mineral Admixture

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.857.105 ◽

2013 ◽

Vol 857 ◽

pp. 105-109

Author(s):

Xiu Hua Zheng ◽

Shu Jie Song ◽

Yong Quan Zhang

Keyword(s):

Pore Structure ◽

Lightweight Concrete ◽

Chloride Ion ◽

Lightweight Aggregate ◽

Total Porosity ◽

Normal Weight ◽

Mineral Admixture ◽

Mineral Admixtures ◽

Aggregate Concrete

This paper presents an experimental study on the permeability and the pore structure of lightweight concrete with fly ash, zeolite powder, or silica fume, in comparison to that of normal weight aggregate concrete. The results showed that the mineral admixtures can improve the anti-permeability performance of lightweight aggregate concrete, and mixed with compound mineral admixtures further more. The resistance to chloride-ion permeability of light weight concrete was higher than that of At the same strength grade, the anti-permeability performance of lightweight aggregate concrete is better than that of normal weight aggregate concrete. The anti-permeability performance of LC40 was similar to that of C60. Mineral admixtures can obviously improve the pore structure of lightweight aggregate concrete, the total porosity reduced while the pore size decreased.

Efficiency factor and modulus of elasticity of lightweight concrete with expanded clay aggregate

Revista IBRACON de Estruturas e Materiais ◽

10.1590/s1983-41952010000200005 ◽

2010 ◽

Vol 3 (2) ◽

pp. 195-204 ◽

Cited By ~ 11

Author(s):

W.G Moravia ◽

A. G. Gumieri ◽

W. L. Vasconcelos

Keyword(s):

Compressive Strength ◽

Modulus Of Elasticity ◽

Large Scale ◽

Lightweight Concrete ◽

Weight Ratio ◽

Lightweight Aggregate ◽

Normal Weight ◽

Empirical Methods ◽

Nowadays lightweight concrete is used on a large scale for structural purposes and to reduce the self-weight of structures. Specific grav- ity, compressive strength, strength/weight ratio and modulus of elasticity are important factors in the mechanical behavior of structures. This work studies these properties in lightweight aggregate concrete (LWAC) and normal-weight concrete (NWC), comparing them. Spe- cific gravity was evaluated in the fresh and hardened states. Four mixture proportions were adopted to evaluate compressive strength. For each proposed mixture proportion of the two concretes, cylindrical specimens were molded and tested at ages of 3, 7 and 28 days. The modulus of elasticity of the NWC and LWAC was analyzed by static, dynamic and empirical methods. The results show a larger strength/ weight ratio for LWAC, although this concrete presented lower compressive strength.

Effect of size on nominal strength of self-compacting lightweight concrete and self-compacting normal weight concrete: A stress-based approach

Materials Today Communications ◽

10.1016/j.mtcomm.2017.08.002 ◽

2017 ◽

Vol 13 ◽

pp. 36-45 ◽

Cited By ~ 10

Author(s):

Mohammad Karamloo ◽

Moosa Mazloom ◽

Gholamhassan Payganeh

Keyword(s):

Lightweight Concrete ◽

Normal Weight ◽

Normal Weight Concrete ◽

Nominal Strength

Characterization of lightweight concrete made of palm oil clinker aggregates

MATEC Web of Conferences ◽

10.1051/matecconf/201825003002 ◽

2018 ◽

Vol 250 ◽

pp. 03002 ◽

Cited By ~ 1

Author(s):

Muhammad Sazlly Nazreen ◽

Roslli Noor Mohamed ◽

Mariyana Aida Ab Kadir ◽

Nazry Azillah ◽

Nazirah Ahmad Shukri ◽

...

Keyword(s):

Mechanical Properties ◽

Palm Oil ◽

Lightweight Concrete ◽

Flexural Modulus ◽

Pulse Velocity ◽

Normal Weight ◽

Fine Aggregate ◽

Test Results ◽

Aggregate Concrete

Lightweight concrete (LWC) has been identified as an innovative technique for construction purposes. Lightweight concrete can be categorized into three different types which are no-fine aggregate concrete, lightweight aggregate concrete and aerated concrete. This paper studied the characteristic of the lightweight concrete in term of mechanical properties utilizing the palm oil clinker (POC) as lightweight aggregates. Two mixes of lightweight concrete were developed, namely as POCC100 and POCC50 where each mix utilized 100% and 50% of total replacement to fine and coarse aggregates, respectively. The fresh and hardened POC concrete was tested and compared to the normal concrete (NC). The hardened state of the concrete was investigated through density test, ultrasonic pulse velocity, cube compressive, splitting tensile, flexural, modulus of elasticity and Poisson's ratio. From density test results, POC falls into the category of lightweight concrete with a density of 1990.33 kg/m3, which are below than normal weight concrete density. The mechanical properties test results on POCC100 and POCC50 showed that the concrete compressive strength was comparable about 85.70% and 96% compared to NC specimen, respectively. For the flexural strength, POCC50 and POCC100 were comparable about 98% and 97% to NC specimen, respectively. While splitting tensile strength of POCC50 and POCC100 was only 0.6% and 4% lower than NC specimen, respectively. In terms of sustainability of solid waste management, the application of the POC in construction will reduce the redundant of by-products resulted from the palm oil industries. After undergoing various testing of concrete mechanical properties, it can be concluded that POC aggregates was compatible to be used in ligtweight concrete mix proportion.

Size Effect in Compressive Strength Tests of Cored Specimens of Lightweight Aggregate Concrete

Materials ◽

10.3390/ma13051187 ◽

2020 ◽

Vol 13 (5) ◽

pp. 1187 ◽

Cited By ~ 1

Author(s):

Lucyna Domagała

Keyword(s):

Compressive Strength ◽

Scale Effect ◽

Lightweight Aggregate ◽

Normal Weight ◽

Cement Matrix ◽

Core Diameter ◽

Aggregate Concrete ◽

Normal Weight Concrete ◽

Strength Tests

The aim of this paper is to discuss the unrecognized problem of the scale effect in compressive strength tests determined for cored specimens of lightweight aggregate concrete (LWAC) against the background of available data on the effect for normal-weight concrete (NWAC). The scale effect was analyzed taking into consideration the influence of slenderness (λ = 1.0, 1.5, 2.0) and diameter (d = 80, 100, 125, and 150 mm) of cored specimens, as well as the type of lightweight aggregate (expanded clay and sintered fly ash) and the type of cement matrix (w/c = 0.55 and 0.37). The analysis of the results for four lightweight aggregate concretes revealed no scale effect in compressive strength tests determined on cored specimens. Neither the slenderness, nor the core diameter seemed to affect the strength results. This fact should be explained by the considerably better structural homogeneity of the tested lightweight concretes in comparison to normal-weight ones. Nevertheless, there were clear differences between the results obtained on molded and cored specimens of the same shape and size.

Pre-Failure Deflection and Residual Load Capacity of Reinforced Lightweight Aggregate Concrete Beams under High-Cycle Fatigue

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.146-147.926 ◽

2010 ◽

Vol 146-147 ◽

pp. 926-936 ◽

Cited By ~ 1

Author(s):

How Ji Chen ◽

Te Hung Liu ◽

Chao Wei Tang

Keyword(s):

Fatigue Testing ◽

Load Capacity ◽

Fatigue Behavior ◽

Lightweight Aggregate ◽

Fatigue Loading ◽

Normal Weight ◽

Rc Beams ◽

Aggregate Concrete ◽

The present study experimentally investigated the pre-failure and post-fatigue behavior of reinforced concrete (RC) beams constructed with lightweight aggregate concrete (LWAC) in comparison with that constructed of normal weight concrete (NWC) of the same compressive strength (40 MPa). A total of twelve RC beams were tested under different fatigue loadings. Based on the experimental observations, the midspan total deflection measured in the fatigue testing consisted of the elastic and plastic components. The mechanismof the two deflection components developed with load cycles was different. The experimental results showed that the fatigue resistance of LWAC beams was better than that of NWC beams for the same fatigue loading levels. It was reflected in both the lower evolution of fatigue damage and the smaller growth of midspan residual deflection. After 2 million cycles, an average increase in residual load capacity of about 8% was found in the NWC beams, while that in the LWA beams remained virtually unchanged.

Comparison of carbonation of lightweight concrete with normal weight concrete at similar strength levels

Construction and Building Materials ◽

10.1016/j.conbuildmat.2007.06.006 ◽

2008 ◽

Vol 22 (8) ◽

pp. 1648-1655 ◽

Cited By ~ 24

Author(s):

T.Y. Lo ◽

W.C. Tang ◽

A. Nadeem

Keyword(s):

Lightweight Concrete ◽

Normal Weight ◽

The influence of OPC and PPC on compressive strength of ALWA concrete

MATEC Web of Conferences ◽

10.1051/matecconf/201819501021 ◽

2018 ◽

Vol 195 ◽

pp. 01021

Author(s):

Fedya Diajeng Aryani ◽

Tavio ◽

I Gusti Putu Raka ◽

Puryanto

Keyword(s):

Compressive Strength ◽

Coarse Aggregate ◽

Lightweight Concrete ◽

Lightweight Aggregate ◽

Normal Weight ◽

Structural Members ◽

Concrete Composition ◽

Normal Weight Concrete ◽

To Come ◽

Seismic Forces

Lightweight concrete is one of the options used in construction in lieu of the traditional normal-weight concrete. Due to its lightweight, it provides lighter structural members and thus, it reduces the total weight of the structures. The reduction in weight resulting in the reduction of the seismic forces since its density is less than 1840 kg/m3. Among all of the concrete constituents, coarse aggregate takes the highest portion of the concrete composition. To produce the lightweight characteristics, it requires innovation on the coarse aggregate to come up with low density of concrete. One possible way is to introduce the use of the artificial lightweight aggregate (ALWA). This study proposes the use of polystyrene as the main ingredient to form the ALWA. The ALWA concrete in the study also used two types of Portland cements, i.e. OPC and PPC. The ALWA introduced in the concrete comprises various percentages, namely 0%, 15%, 50%, and 100% replacement to the coarse aggregate by volume. From the results of the study, it can be found that the compressive strength and the modulus of elasticity of concrete decreased with the increase of the percentage of the ALWA used to replace the natural coarse aggregate.

Rehabilitation of Hybrid RC-I Beams with Openings Using CFRP Sheets

Civil Engineering Journal ◽

10.28991/cej-2022-08-01-012 ◽

2022 ◽

Vol 8 (1) ◽

pp. 155-166

Author(s):

Ali I. Salahaldin ◽

Muyasser M. Jomaa’h ◽

Nazar A. Oukaili ◽

Diyaree J. Ghaidan

Keyword(s):

Lightweight Concrete ◽

Normal Weight ◽

Reinforced Concrete Beams ◽

Bottom Flange ◽

Normal Concrete ◽

Normal Weight Concrete ◽

Concrete Members ◽

Hybrid Beams ◽

The Difference ◽

Total Capacity

This research presents an experimental investigation of the rehabilitation efficiency of the damaged hybrid reinforced concrete beams with openings in the shear region. The study investigates the difference in retrofitting ability of hybrid beams compared to traditional beams and the effect of two openings compared with one opening equalized to two holes in the area. Five RC beams classified into two groups, A and B, were primarily tested to full-failure under two-point loads. The first group (A) contained beams with normal weight concrete. The second group (hybrid) included beams with lightweight concrete for web and bottom flange, whereas the top flange was made from normal concrete. Two types of openings were considered in this study, rectangular, with dimensions of 100×200 mm, and two square openings with a side dimension of 100 mm. A full wrapping configuration system for the shear region (failure zone) was adopted in this research. Based on the test results, the repaired beams managed to recover their load carrying capacity, stiffness, and structural performance in different degrees. The normal concrete beam regains its total capacity for all types of openings, while the hybrid beams gain 84% of their strength. The strength of hybrid concrete members compared with normal concrete is 81 and 88% for beams of one opening and two openings, respectively. Doi: 10.28991/CEJ-2022-08-01-012 Full Text: PDF

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

Proceedings of International Structural Engineering and Construction ◽

10.14455/isec.res.2020.7(1).mat-10 ◽

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 ◽

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.