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Review
. 2020 Mar 3;13(5):1120.
doi: 10.3390/ma13051120.

Lightweight Concrete-From Basics to Innovations

Karl-Christian Thienel  1 , Timo Haller  1 , Nancy Beuntner  1
Affiliations
Review

Lightweight Concrete-From Basics to Innovations

Karl-Christian Thienel et al. Materials (Basel). .

Abstract

Lightweight concrete has a history of more than two-thousand years and its technical development is still proceeding. This review starts with a retrospective that gives an idea of the wide range of applications covered by lightweight concrete during the last century. Although lightweight concrete is well known and has proven its technical potential in a wide range of applications over the past decades, there are still hesitations and uncertainties in practice. For that reason, lightweight aggregate properties and the various types of lightweight concrete are discussed in detail with a special focus on current standards. The review is based on a background of 25 years of practical and theoretical experience in this field. One of the main challenges in designing lightweight concrete is to adapt most of design, production and execution rules since they often deviate from normal weight concrete. Therefore, aspects are highlighted that often are the cause of misunderstandings, such as nomenclature or the informational value of certain tests. Frequently occurring problems regarding the mix design and production of lightweight concrete are addressed and the unintended consequences are described. A critical view is provided on some information given in existing European concrete standards regarding the mechanical properties of structural lightweight concrete. Finally, the latest stage of development of very light lightweight concretes is presented. Infra-lightweight concrete is introduced as an innovative approach for further extending the range of applications of lightweight concrete by providing background knowledge and experiences from case records.

Keywords: ILC; LAC; LC; LWA; infra-lightweight concrete; lightweight aggregate; lightweight aggregate concrete; lightweight concrete; mix design; production.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Correlation between strength classes and necessary dry density for LC [40,41].
Figure 2
Figure 2
(a) Image of structural lightweight concrete (LC) with a dense matrix structure; (b) Image of the lightweight aggregate concrete (LAC) with open pore structure; (c) Image of LAC with a porous matrix filling the open pore structure. All three types of lightweight concrete are based on expanded clay from one producer as LWA.
Figure 3
Figure 3
Severe formation of microcracks in the matrix (marked with red arrows) of a high strength LC due to water absorption of fine and coarse LWA (Courtesy: Andrea Kustermann).
Figure 4
Figure 4
SEM image of the interfacial transition zone in lightweight concrete between an expanded clay aggregate and the paste. Hydration products are visible inside the outer LWA pores [97].
Figure 5
Figure 5
Explanation of limit strength (flc,lim) of different types of lightweight and normal weight aggregate [64].
Figure 6
Figure 6
Conversion factors between 150-mm cubes and 300/150-mm cylinders for LC tested at 7 d, 28 d and 90 d. The specimens were cured under water [116] or in a climate room (20 °C/65% relative humidity) following the German national annex to [116] [64].
Figure 7
Figure 7
Conversion factors between specimens cured under water [116] or in a climate room (20 °C/65% relative humidity) following the German national annex to [116] for different specimens sizes, shapes and testing ages [64].
Figure 8
Figure 8
Correlation between 28-day cube strength and dry density for lightweight concretes with different compositions [6].
Figure 9
Figure 9
Correlation between 28-day cube strength and dry density for lightweight concretes (LC) with lightweight sand [143], lightweight aggregate concrete (LAC) with porous matrix different compositions [43], data for two ILC projects [18,48] and most recent LAC-based ILC projects [49].
Figure 10
Figure 10
Correlation between thermal conductivity and dry density for LC, LAC taken from technical approvals [140,141], data published for several LC and two ILC projects [18,48] as well as for most recent LAC-based ILC projects [49].
Figure 11
Figure 11
Surface texture of executed ILC projects. Perfectly smooth surface (a); rough saw surface (b); porous (vivid) surface (c) (courtesy: Björn Callsen and Werner Rothenbacher)
Figure 12
Figure 12
Truck-mounted concrete plant for ILC (courtesy: Björn Callsen).
Figure 13
Figure 13
Map of Germany showing locations where ILC-projects have been realized until end 2019.
See this image and copyright information in PMC

References

    1. Lamprecht H.-O. Opus Caementitium: Bautechnik der Römer. 5th ed. Beton-Verlag GmbH; Düsseldorf, Germany: 1996. p. 264.
    1. Chandra S., Berntsson L. Lightweight Aggregate Concrete. 1st ed. Noyes Publications; Norwich, UK: 2002. p. 450.
    1. Expanded Clay and Slate Institute . Lightweight Concrete History Applications Economics. Expanded Clay and Slate Institute (ESCSI); Salt Lake City, UT, USA: 1971.
    1. Holm T.A. Performance ol Structural Lightweight Concrete in a Marine Environment; Proceedings of the Performance of Concrete in Marine Environments; St. New Brunswick, NB, Canada. 1 August 1980; pp. 589–608.
    1. Raithby K.D., Lydon F.D. Lightweight concrete in highway bridges. Int. J. Cem. Compos. Lightweight Concr. 1981;3:133–146. doi: 10.1016/0262-5075(81)90007-5. - DOI

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