Lightweight Concrete—From Basics to Innovations

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.

Mechanical Properties of Chopped Basalt Fiber-Reinforced Lightweight Aggregate Concrete and Chopped Polyacrylonitrile Fiber Reinforced Lightweight Aggregate Concrete

“…In that regard, the definition of a constant weight for LWAC is a weight loss of less than 0.1%. Cubic samples with dimensions of 100 × 100 × 100 mm 3 were used to test water absorption. Specimens were soaked in water after drying to a constant weight and measured the weight since soaking time reach 1 h, 3 h, 6 h, 12 h, 24 h and 48 h, respectively.…”

“…Lightweight aggregate concrete (LWAC) has become a main development focus in the construction field, owing to its low density, high strength and excellent durability [1][2][3]. Moreover, artificial lightweight aggregates, which are manufactured from industrial wastes, river silts and solid wastes, are important sources for green building and sustainable development [4][5][6].…”

The The Effects of Structural Lightweight Concrete on Energy Performance and Life Cycle Cost in Residential Buildings

“…Lightweight concretes produced by creating voids in different ways in concrete or using lower unit weight aggregates compared to normal aggregates have a history of more than two thousand years [21]. In lightweight concrete production, lightweight aggregates with high pore amounts are used compared to normal aggregates.…”

Lightweight Reactive Powder Concrete Containing Expanded Perlite

“…Lightweight aggregates applied to concretes, according to the definition included in PN-EN 206+A1:2016-12 standard, have the density of <2000 kg/m 3 in an oven-dry condition, or loose bulk density of <1200 kg/m 3 [1]. They may be divided into natural lightweight aggregates which include volcanic tuff, scoria, or perlite, and artificial (processed) lightweight aggregates that include expanded clay, expanded perlite, expanded shale, lightweight aggregate from processed fly ash, or vermiculite [2].…”