Types Of Lightweight Concrete Research Articles

Comparative Study of the Lightening of Concrete Through the Use of Recycled Tire Rubber and Expanded Clay Aggregate

Abstract The waste of tire rubber is characterized by the generation of huge amounts, which is annually discarded. This waste causes problems for human health and the environment. Thus, the valorization of recycled tire rubber in concrete production is considered as an alternative and sustainable solution. This experimental work is a comparative study, which aims to investigate the possibility of using recycled tire rubber as a fine aggregate in the production of lightweight concrete. To achieve this objective, two types of lightweight concrete containing (35, 70 and 100%) of expanded clay and (5, 10 and 15%) of recycled tire rubber as a fine aggregate were produced. Their fresh properties were investigated using slump, density and air content tests, while the hardened properties were investigated by compressive strength, flexural strength, ultrasonic pulse velocity, and water absorption tests. The results obtained showed that the utilization of both expanded clay aggregate and recycled tire rubber leads to a reduction in density and mechanical strength but increases the porosity of lightweight concrete. However, the lightweight concrete containing the expanded clay aggregate had a higher efficiency factor than those containing recycled tire rubber.

Foamed Concrete using Red Gypsum and Palm Oil Fuel Ash: A Sustainable Building Material

Concrete is the most commonly used building material. Even then, it has a drawback that it hasheavy density. Hence, researches are progressing everywhere to develop a new building material, which has low density, less water absorption as well as economical. And here lies the importance of foamed concrete. Foamed concrete is a type of lightweight concrete in which stable foam is used as the main ingredient. Stable foam is produced from standard foaming agent using a foam generator. The peculiarity of foamed concrete is that no coarse aggregate is used in it. An attempt is made in this research to use palm oil fuel ash as a partial replacement for cement and red gypsum as a partial replacement for manufactured sand. Both of these materials are waste materials and are abundantly available. The concrete made up of this will be more sustainable as well as economical. By adjusting the addition of stable foam, foamed concrete of various densities can be developed. Foamed concrete blocks made up of these materials can be used for load bearing as well as non-load bearing masonry works. It has been observed that the addition of Palm Oil Fuel Ash and Red Earth has improved the properties of foamed concrete.

PENGARUH PENAMBAHAN SERAT POLYPROPYLENE TERHADAP KUAT TEKAN FOAM CONCRETE

Lightweight concrete has a specific gravity of 400 - 1,600 kg/m3 so it has a lower weight than normalconcrete. One type of lightweight concrete is foam concrete which is formed by adding air to the concretemixture. The compressive strength of foam concrete is still very low. With the addition of polypropylenefibers can increase the compressive strength of the concrete. The value of the compressive strength offoam concrete with a mixture of 0% polypropylene fiber shows a value of 2.85 MPa. The addition of 0.2%fiber showed a value of 7.77 MPa. The percentage of 0.4% polyoropylene fiber has a compressivestrength of 8.38 MPa.

Application of sawdust concrete in construction

Sawdust concrete is a type of lightweight concrete in which some of the mineral aggregate is replaced by sawdust - a by-product of wood processing. It is not a new material, but its potential is not utilised to its full degree. Taking into account the most important advantages of sawdust concrete - lower density and greater thermal and acoustic insulation than ordinary concrete - it is worth to consider the possibilities of its usage in construction  wider than currently . In order to present the properties of sawdust concrete, the review of contemporary technical literature has been performed.
 For the production of sawdust concretes mineralized sawdust from various types of trees, ordinary cements, mineral aggregates and water, are used. The usage of additives and admixtures is also allowed. The properties of the finished sawdust concrete are mainly influenced by the proportion of its components, especially the amount of fine aggregates replaced by sawdust. The construction products made of sawdust concrete are characterized by a low coefficient of thermal conductivity λ and soundproofing properties. In bending tests, a simply supported sawdust concrete beam behaves similar to a regular concrete beam, cracks first appear in the tension zone. Tensile strength, compressive strength and Young's modulus of sawdust concrete products depend on the proportion of components and the method of sawdust preparation before applying in the sawdust concrete-mix. Compared to ordinary concrete, the obtained values for sawdust concrete are lower, but partially fall within the ranges for the lower classes of ordinary concrete.
 There are several possible applications of sawdust concrete in construction. One of the perspectives is to use it to build walls in buildings that require soundproofing between rooms, or to replace wood with it when renovating old buildings. However, further tests of sawdust concrete are needed in terms of the most favourable composition for its mechanical properties, and to define the standards according to which sawdust concrete elements should be produced.

Pull-off bond strength of novel wide rounded ends fiber and impact of fiber stretching on fiber/matrix frictional-slip bond strength

ABSTRACT This paper presents a study about fiber slippage behavior under direct pull-out and assessment of fiber/matrix pull-off bond strength. This study was prepared through theoretical calculations validated by experimental tests. Theoretically, the study shows a general solution for the fiber-slip mechanism in a general matrix using a new frictional-shear-lag model and an analytical model for pull-off bond strength. Experimentally, pull-out tests were conducted for selected types of single fiber in micro-level (glass, carbon, and short-steel fiber); and macro-level (straight steel fiber). The results showed significant improvements in the pull-off bond strength using novel shape of fiber with wide rounded ends-WESF. The pull-off bond strength in normal-weight concrete was found lower than in lightweight concrete, and the matrix with higher compressive strength improves the pull-off bond strength. Also, the steel fiber showed higher pull-off bond strength compared to glass and carbon fiber; whereas the efficiency of short-steel fiber was higher than the long one. All types of fiber showed that the higher aspect ratio reduces the pull-off bond strength. Using the novel-WESF, the performance of fiber-slip improved 52.65% in normal-weight concrete. Moreover, the fiber-slip performance improved 61.79% in sand-lightweight concrete, and 70.20% in all other types of light-weight concrete.

Experimental investigations and numerical simulations of the vibrational performance of composite timber-lightweight concrete floor structures

The dynamic behavior of timber and lightweight concrete composite floor structures was examined in this paper. The need to reduce the additional load on the existing foundations of the structure, leads to the increasing use of lightweight concrete in the rehabilitation and reconstruction of buildings. The aim of this paper is to examine the basic dynamic characteristics of timber floor structures repaired with lightweight concrete of various volumetric densities. The dynamic behavior was analyzed in a way that the first three natural frequencies of four floor composite structures with identical cross sections and fasteners, but with different class of lightweight concrete volumetric density in the upper concrete slab, were calculated. Preliminary laboratory testing of the relevant properties of four types of lightweight concrete, timber and fasteners, which were used in the bonding of timber and lightweight concrete, provided the necessary input data for numerical research. For analytical research, a simple method of dynamic calculation of natural frequencies of elastically coupled structures has been proposed. The accuracy of the results of the proposed dynamic calculation was confirmed experimentally, and by comparison with the results of the Ansys software package.

Mechanical Behaviour, Properties and Characteristics of Foamed Cellular Concrete: A Review

Foamed cellular concrete (FCC) is a type of lightweight concrete. Traditionally, it has been used for insulation and void filling. However, in the last years, the possibility of obtaining high strength FCC has motivated the study of its structural use. The novelty and uniqueness of this article is to provide a review of the most important aspect of FCC including component materials, design and mix elaboration, physical properties and mainly, its mechanical behaviour. Also, in order to achieve a global understanding of the material and its characteristics, advances regarding its physical properties are collected: density, porosity, thermal, acoustic and water insulation, durability, fire resistance and drying shrinkage. Then mechanical properties such as elastic modulus, compressive, tensile, bending and shear behaviour, are analysed. The literature review also aims to evaluate the influence of using inert and active mineral additions, fibers and chemical additives to improve its mechanical and physical properties. Based on the work done, research needs have been identified: there are no prediction models for stress-strain behaviour with complete curves for FCC in compression nor in traction, the performed numerical modelling is scarce, use and effect of chemical additives is a not far studied, long-term tests are scarce or nil, the evaluation of resistance in different aggressive environments has not been sufficiently evaluated.

KAPASITAS GESER BALOK PROFIL I FERRO FOAM CONCRETE

Lightweight concrete has a lower density than regular concrete. Foam concrete is one type of lightweight concrete. Aceh is one of the earthquake-prone provinces in Indonesia. Ferro foam concrete as a material to reduce the risk of earthquakes is an option. Ferro Foam Concrete is a composite material that combines wire mesh and foam concrete . Aside from its high load carrying capacity, lightweight, and ease of manufacture, this material have several advantages. Afifuddin et al. researched Canal Profile (C) configured to I using Ferro foam concrete (2013-2014). According to the findings of this study, the girder's weakness was that it experienced flexural failure during the test and that the ability of the girder as the I profile was not fully achieved due to the merging of two C profiles. The I profile does not fully achieve the size of the wings and body, which is calculated as an integral part of the I profile. As a result of this issue, the author wishes to conduct additional research on the subject. This research aimed to determine the shear capacity of the load-receiving system. The I Profile is the first of three samples to be created. BU 1 has three layers of wiremesh and measures 225 mm wide, 450 mm high, and 90 mm thick. BU 2 has four layers of wiremesh and measures 225 mm wide, 450 mm high, and 90 mm thick. Speciments 3 has four layers of wiremesh and is 300 mm wide, 600 mm high, and 120 mm thick. Reinforcement of test samples with D8 mm and D13 mm (steel screws) and wiremesh 3, 4, and 4 layers. SG 1.6 with FAS 0.4 and pozzolan at 10%. The results of the research on the shear capacity of the profile I 450-225-90-3L from the laboratory results were 11,855 tons, and from the theoretical obtained 12.007 tons. For the I profile of 450-225-90-4L, the laboratory results have a shear capacity of 12.730 tons. In comparison, the theoretical yield is 13.394 tons, and the shear capacity for the I profile of 600-300-120-4L is 21.150 tons and based on theoretical 24.462 tons.

Exploring the suitability of using Foam concrete as pore pressure dissipation measure for slope Stability: A state of art review

Landslides are one of the major factors leading to disruption of transportation and urbanization of north-eastern India (NEI). The primary reasons are continuous precipitation and alarming seismicity at frequent intervals. Among various factors which can trigger landslide, most common is the increase of pore water pressure (PWP). This in turn increases the weight of the backfill and subsequently contribute to the overturning moment. Hence, measures to extract the pore water (PW) from the backfill through provision of drainage path is an efficient and widely followed approach to mitigate landslides. This paper presents a detailed overview on various landslides which have happened in the NEI during rainfalls and earthquake events, confirming these as two main triggering factors. Later, the limitations of various conventional landslide prevention techniques is also discussed. Though RWs are commonly adopted slope stabilization techniques, many case studies exist in where even RWs had failed to stabilize the slopes particularly where the slopes with higher groundwater table were subjected to heavy precipitation. The primary reason of failure was development of excess PWP behind RWs. While weep-holes in the RW play a critical role in dissipating PWP of the backfill, these are clogged resulting in the failure of the RWs. The fact cannot be denied that the effectiveness of the weep-hole depends upon its design, construction as well as its maintenance.Recently few researchers have shown that the Foam concrete (FC), a type of lightweight concrete, act as an excellent draining material to facilitate PW discharge for slope stabilization owing to its high permeability. Further, as the density of air voids in FC is more, rate of clogging is expected to be lesser, thus demanding lesser maintenance when compared to conventional weep-holes. This way, the need of regular maintenance of weep-holes can be minimized by use of FC. It should be highlighted here that though FC has lot of potential to be use in aforementioned application, there is not much of research exist in the literature on use of FC for PWP dissipation application. In this light, the present work also presents an in-depth review on permeation characteristics of FC, enumerating the PWP dissipation mechanism with the help of case studies from the literature.

Investigation on properties of aerated concrete with foundry sand as replacement for fine aggregate

Precast Elements can help in fast track construction. Lightweight concrete can be customized for higher strength to be used as precast elements in construction industry. There are many types of lightweight concrete among which aerated concrete is one type. Concrete having density lower than 1200 kg/m3 is termed as lightweight concrete It is light weight due to the isolated air voids formed in the matrix by using aerating agents like aluminium powder and hydrogen peroxide. The fine aggregate used in aerated concrete is to be pulverized in order to enable the release of hydrogen or oxygen that is released due to the reaction of aerating agent with calcium in cement. This type of concrete has air voids distributed in the matrix resulting in low strength. The objective of this study is to use foundry sand as replacement to river sand as the demand of naturally available material is high leading to depletion of natural resources. Experimental trials were carried out by substantial replacement of river sand with foundry sand. Aluminium powder was used as the aerating agent as it liberates H2 gas due to the reaction with Ca in cement. The strength of conventional concrete was 10 MPa and with addition of foundry sand up to 40% there was increase in strength of about 12.5 MPa. It was observed that beyond 40% replacement of sand with foundry sand there was strength reduction. The tensile strength and bending strength was also tested and it resulted in 1.91 and 1.98 MPa respectively. Durability testing was carried out to find the sorptivity of the concrete. Also the distribution of voids in the matrix and investigation of pore size was determined using image analysis. The air voids due to the aerating agent results in forming isolated air voids which does not pose much problem in terms of durability. The commercial lightweight aerated blocks have strength ranging from 4 to 6 MPa whereas this optimized mix resulted in strength of 12.5 MPa. Hence the results of this study shows that foundry sand cab be used to a certain extent to save the consumption of natural resources.

Production of Lightweight Concrete by Using Polystyrene (cork) waste

There are two important subjects in the local and global areas, the first is the environmental pollution and the second is economic advantages of recycling and reusing of industrial materials. One of the most important industrial materials is cork waste. Because of many good properties of cork, like compressibility and a good ability to mould according to human needs, this material become as an important material in several life categories. This research work includes production of new type of light weight concrete and studies the mechanical and thermal properties. Several proportions of raw materials were used to produce this type of concrete. This study is intended to produce light weight concrete with low thermal conductivity so that it can be used for concrete masonry units. Polystyrene aggregate was added as percentages by weight of cement to improve the thermal properties of this type of concrete. Mechanical, and thermal tests with difference ages were made in this work. For polystyrene concrete with polystyrene cement ratio (p/c) of (2.67 – 6)%, the 28-day compressive strength range is from (4.31 – 2.67)MPa, flexural strength range is from (3.05-1.719) MPa, density range is from (1493-1213) kg/m3, and thermal conductivity range is from (0.91-0.782)% as a percentage by that of reference mix. The study show suitability of this type of concrete to be used in concrete masonry units of non-bearing walls.

Sustainable Usage of Waste Materials in Aerated and Foam Concrete: A Review

The utilization of waste materials in concrete is now a widely used concept that counteracts the depletion of natural resources. In addition to this, it will untangle the disposal of waste materials in nature and find an alternative approach to shelter the environmental resources. Due to rapid growth in industrialization, waste management has become increasingly challenging in recent years. Several waste materials could be used in whole or in part to replace cement or aggregates. The main disadvantage of conventional concrete is its increased self-weight. The paper summarizes the current knowledge of two types of lightweight concrete, viz aerated and foam concrete that can be made less dense than conventional concrete and the possibility of using waste materials. The usage of admixtures like Fly ash, GGBS, silica fume, and waste materials like quarry dust, rubber particles, rice husk ash, plastic waste, glass powder, and foundry sand is examined. The effective use of waste materials in lightweight concrete is reviewed by evaluating properties such as workability, elastic modulus, compressive strength, flexural strength, and microstructural characteristics. The optimum percentage of Fly ash, GGBS, silica fume, and rice husk ash is found to be 20%, 50 -75%, greater than 10%, and 20 – 30%, respectively. Out of different types of plastic waste used in concrete, PVC granules that pass 5mm sieve size are used to prepare lightweight aggregate concrete, which exhibits a density of around 1500kg/m³. The quarry dust is the best option for an acceptable aggregate replacement at 20% in foam concrete. The studies show a drastic increment in compressive strength and capillary absorption is also increased to 14% than conventional cement, which reduced the risk of early-age cracking. Fine aggregate replaced of glass powder exhibits delay in setting time at higher percentages. While using 20% of fine aggregate substituted with foundry sand yields comparable results to the control specimen in terms of their mechanical properties

ВЫСОКОПРОЧНЫЕ БЕТОНЫ ДЛЯ ЛЕГО-БЛОКОВ

Lego technology is one of the modern construction solutions providing cost reduction, increasing architectural expressiveness and the pace of work. This is the development of groove-ridge positioning systems and connection of small-piece wall elements. Currently, the technology of Lego blocks is implemented on various types of building materials: ceramic and hyper-pressed non-fired bricks, blocks from various types of lightweight concrete, which have not found wide practical application due to an obvious shift in the balance of properties either towards aesthetics – brick, or thermal insulation - blocks. In this regard, a technology for producing multi-hollow thin-walled lego blocks based on self-compacting high-strength fine-grained concrete with various types of high-porous filling is proposed. In this paper, the compositions of high-strength concrete mixes for the manufacture of lego block frames are proposed. The main emphasis in the development is made on improving the manufacturability of their production and the maximum efficiency of using the clinker component. Overcoming the multicomponent problem is achieved by replacing traditional cement with a special all-in-one composite binder. Due to the unacceptability of traditional methods of dispersed reinforcement for producing thin-walled products from self-compacting fine-grained mixtures, it is proposed to carry out dispersed micro-reinforcement at the level of cement stone, for which a technology is developed and the optimal parameters of dispersion of glass and basalt fiber are determined. Thanks to this approach, reinforcing fibers are included in the composition of the composite binder itself, which ensures maximum manufacturability and an increase in compressive strength up to 20...25 %.

Investigation of waste EPS foams modified by heat treatment method as concrete aggregate

The method for the recycling of expanded polystyrene foam (EPS) in waste state, which causes a significant environmental pollution, is presented in this study. With this method, modified EPS aggregate was produced by heat treatment applied on 10 × 10 × 10 mm EPS aggregates and the production of a new type of lightweight concrete was aimed by means of being used instead of sand. This disadvantage of EPS aggregate concretes with low compressive strength values has been turned into an advantage through heat treatment method. In this method, the heat treatment process temperatures were determined as 75 °C, 100 °C and 125 °C, while the durations of processes were determined to be 15, 30, 45 and 60 min. The ideal heat treatment temperature and time is determined to be 15 min at 125 °C. 16 samples with various aggregate rates were produced, and the following results were obtained from the tests carried out: i) During 15 min of heat treatment at 125 °C, while the volume change decreased by 12 times, the unit weight increased by 21 times and turning into the form of a synthetic lightweight aggregate. ii) Modified EPS aggregated concretes can be used in building parts where semi-carrier lightweight concrete is required with its strength (with values of 12.66–15.83 MPa up to 40% volumetric ratio. iii) Thermal conductivity coefficients of new concretes vary between 0.154 and 0.481 W/mK. It is conferred that modified EPS aggregate concretes can be used both for insulation purposes and as semi-carrier lightweight concrete.

Flexural performance of reinforced carbon nanofibers enhanced lightweight cementitious composite (CNF-LCC) beams

As a type of lightweight concrete, foam concrete is traditionally used for non-structural applications due to its poor mechanical properties. However, in recent years, there is a surge in interest in potential applications of foam concrete as structural components due to its low self-weight, homogenous foam bubble distribution, self-compacting, saving in raw materials, good thermal and acoustic insulation. The main challenge for foam concrete is to have high-performance pore walls to provide required mechanical properties, shrinkage resistance, and durability under reduced density. A new type of foam concrete termed as carbon nanofibers enhanced lightweight cementitious composite (CNF-LCC) was developed and reported to have excellent mechanical properties, bond strength with steel reinforcement, durability and shrinkage resistance compared with traditional foam concrete. In this paper, the flexural performance of 8 reinforced CNF-LCC beams was investigated. Test parameters included the amount of carbon nanofibers (CNFs), tension and compression reinforcement ratios, and steel link ratio. The flexural performance of reinforced CNF-LCC beams was comparable with that of normal weight concrete (NWC) and lightweight aggregate concrete (LWAC) and even exceeded traditional foam concrete. The usual reinforcement detailing for NWC beams can be equally employed on CNF-LCC beams. Incorporation of CNFs produced varying degrees of improvement on flexural response especially ductility of beams. Finally, predictions from standard codes and the proposed model agreed well with the test results.

Assessment of strength and deformation of lightweight concrete and its components under triaxial compression, taking into account the macrostructure of the material

The paper presents the results of experimental studies on the strength and deformations of lightweight concrete, mortar matrix and hardened cement paste under triaxial compression. Tests on samples were carried out using short-term triaxial proportional σ1 > σ2 = σ3 loading (i.e. axial compression + lateral hydrostatic pressure). During the loading, the ratio of the main stresses (both axial and lateral) was kept constant up to the end of tests. The experimental studies were carried out for different low ratios of σ2/σ1. A theoretical estimation has been discussed to approximate experimental results and prediction of triaxial strength values for different types of lightweight concrete. An estimation of the confining pressure parameter K has been done for the used mode of loading.

The relationships between compressive strength and density of polystyrene lightweight concrete and their component ratios

The research deals with the compressive strength and density of lightweight concrete, made from polystyrene, cement, sand and water. This type of lightweight concrete is characterized by good thermal insulation, low density and good compressive strength and it is used as a lining material in inclination surfaces and in the production of unloaded building units and elements. The aim of this paper is to suggest mathematical relationships between compressive strength, density and mix proportions. An intensive experimental program has been implemented for this purpose. The investigated variables were the mix proportions, namely, polystyrene to cement ratio (P/C), sand to cement ratio (S/C) and water to cement ratio (W/C). Sixty mixes were produced and tested using five polystyrene to cement ratios (P/C), 0.02, 0.03, 0.04, 0.05, 0.06 four sand to cement ratios (S/C), 2.5, 3, 3.5, 4 , and three water to cement ratios (W/C), 0.35, 0.40, 0.45. From the test results, mathematical relationships were suggested that can be of use in determining mix proportions of polystyrene lightweight concrete based on the required compressive strength or based on the required dry density.

Experimental Investigation of the Production of Sustainable Lightweight Concrete

An experimental study on four types of coarse aggregate was conducted to produce lightweight concrete. These four types are namely; white limestone, red limestone, clay brick fragments, and pumice. Ordinary Portland cement was used for all examined mixes. Water to cement ratio (w/c) was modified according to the effect of coarse aggregate type on the workability of the resulted concrete for each mix. The reference concrete mix, which is normal concrete, water to cement ratio used was (0.5). The investigated characteristics for all concrete mixes were workability, compressive strength, dry density, absorption, and thermal conductivity. Results indicated that the aggregate type significantly affects most of the properties of lightweight concrete mixes such as workability, density, and thermal insulation for all tested types of concrete. All investigated specimens indicated improvement in terms of density, workability, and thermal conductivity when compared to the reference concrete mix. Yet, it was derived from the testing results that using pumice in lightweight concrete production is the optimum option among the other examined types. When compared to normal concrete, this type of lightweight concrete showed a 41% decrease in dry density, nearly 72.54% decrease in thermal conductivity, and about 12% increase in workability. However, it is vital to notice that due to the low compressive strength and the relatively high absorption capability for all the examined types of lightweight concrete, it is suggested to use these types of concrete for non-structural walls that are not subjected to or exposed to high humidity.

Formulation and characterization of geopolymer and conventional lightweight green concrete by incorporating synthetic lightweight aggregate

The present work was designed to develop green lightweight aggregates (LWA) using; coal fly ash, granulated blast furnace slag and small amount of cement (10–20%). Two types of lightweight concrete (LWC) were formulated using developed synthetic LWAs i.e. (i) geopolymer (GC), and (ii) Portland cement concrete (PC). Physical and mechanical properties of both LWAs and LWCs were examined for their suitability to produce LWC. Test results indicated that, density of LWA was increased and water absorption value was decreased with higher cement percentage in the developed pellet, which were complying with the ASTM requirements for LWA. Mechanical strength of produced LWAs was approximately 50% of the natural coarse aggregate. Considering LWC results, the density of LWCs was less than the threshold value (<2000 kg/m3). The compressive strength, ultrasonic pulse velocity and split tensile strength of GC were higher than PC and they were more for concretes containing LWA with higher cement percentage. Experimental strength was also compared with predicted strength from different empirical models. Overall, the properties of LWA and resulting LWC were appropriately acceptable and can offer sustainable solution to the construction industry, especially for green concrete.

Lightweight Concrete-From Basics to Innovations.

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.