Formwork Elements Research Articles

An Assessment of the Impact of Protective Lifeline Safety Systems on Formwork Systems

Work related to the installation of formwork and the pouring of concrete involves the need to move on the formwork walls. There is a high risk of falling off the wall and falling during work. It is therefore necessary to use systems that allow for safe work at heights, but also the safety of the formwork systems themselves. This article presents the results of tests under real conditions of a person falling from the formwork. Two safety systems were tested: one based on a pole–rope system with a flexible joint and one based on climbing arrester hooks. The test results showed that the additional forces occurring in the system do not exceed 6.4 kN and that the stresses reach the highest value only at the site of installation of the system and do not exceed the yield strength of the steel used in the formwork structure. The results obtained indicate that during a fall, the fall energy is absorbed so much that there is no damage to the formwork elements, and the highest effort is observed for the formwork arrester hook and reaches 87% of the structure effort. In the case of systems with flexible posts, the maximum load values do not exceed 30% of the structure. The presented results may be useful in designing and planning assembly works and using formwork systems in concrete pouring conditions.

Structural design and engineering of Striatus, an unreinforced 3D-concrete-printed masonry arch bridge

This paper describes the structural design and engineering of “Striatus”, a 3D-concrete-printed unreinforced masonry pedestrian bridge built in Venice in 2021 as part of the Time Space Existence exhibition organised by the European Cultural Centre. The project combines the latest developments in 3D concrete printing with the structural principles of historic unreinforced masonry. Typically, the structural applications of 3D concrete printing are limited to elements such as columns and walls loaded vertically, perpendicularly to the horizontal printing layers, to formwork elements or secondary structural elements. Indeed, fabrication constraints, delamination issues and the low tensile strength of the concrete have been seen as limiting factors to 3D concrete printing for structural applications demanding resistance to bending or predominant loading directions not perpendicular to the printing layers. By using unreinforced-masonry structural principles, this paper shows that structural elements spanning space horizontally, such as a pedestrian bridge, can be built by using the 3D concrete printing components as the main structure, working only in compression, loaded perpendicularly to the printed layers. Furthermore, as a compression-only structure following masonry principles, Striatus enabled the use of unreinforced concrete without any mechanical or chemical connections between the elements and the separation of concrete and steel, only used for the supports and to equilibrate the horizontal thrust of the arch effect through the tension ties. This work shows how the application of unreinforced masonry principles to 3D concrete printing offers new opportunities in terms of structural design and represents a strategy to increase sustainability by reducing material consumption and allowing reusability and recyclability of the structure. Finally, this paper discusses the critical aspects related to the design of Striatus from an engineering and construction point of view.

Locking Mechanism for Connecting Elements of Non-Removable Formwork

Purpose of research. Locking mechanisms have been widely used to connect elements of vertical formwork structures consisting of metal frames and shields fixed to them. The purpose of the study is to develop the design of the locking mechanism for the elements of removable formwork, which has high technological characteristics. A patent search was conducted for existing design solutions to ensure the connection of elements of removable formwork. It has been revealed that the most common structures used in the locking mechanisms of removable formwork elements are rack-and-pinion structures. The analysis of existing structures is carried out, the shortcomings of existing devices are revealed. It is established that the existing designs of locking mechanisms for connecting elements of removable formwork have low manufacturability of individual elements. In this regard, in order to solve the research problem, the design of the locking mechanism was developed, which ensures the connection of the elements of the removable formwork. A distinctive feature of the application of the new design of the locking mechanism for connecting the elements of removable formwork is the use of a new design of the toothed rail, which is more technologically advanced in manufacturing, compared with existing designs. Another distinctive feature is the use of a wedge with smooth edges, which also increases the manufacturability of the construction of the device for connecting the elements of removable formwork. To achieve this goal, an analytical research method was applied. The use of the proposed design will increase the manufacturability of the manufacture of locking mechanisms for connecting elements of removable formwork. The proposed design of the locking mechanism for connecting the elements of removable formwork, developed as a result of the study, has design features related to operating conditions. These features will be considered as a result of further research.Methods. Simulation modeling methods were used to conduct the experiments.Results. The range of sizes of the main structural elements of the locking mechanism for connecting the elements of removable formwork, ensuring the operation of the device under the action of design loads, is determined.Conclusion. The results of the study showed that the existing designs of locking mechanisms for connecting elements of removable formwork have disadvantages, one of which is the low manufacturability of the devices. The design of the locking mechanism has been developed, which provides higher manufacturability. The proposed device can be used in construction to connect elements of fixed formwork.

Mineral composites: stay-in-place formwork for concrete using foam 3D printing

Optimizing the shape of concrete construction elements is significant in reducing their material consumption and total weight while improving their functional performance. However, the resulting non-standard geometries are difficult and wasteful to fabricate with conventional formwork strategies. This paper presents the novel fabrication method of mineral foam 3D printing (F3DP) of bespoke lost formwork for non-standard, material-efficient, lightweight concrete elements. Many innovative formwork studies have shown that stay-in-place formwork can help to reduce waste and material consumption while adding functionality to building components. Foams are particularly suitable for this application because of their high strength-to-weight ratio, thermal resistance, and good machinability. F3DP allows the waste-free production of geometrically complex formwork elements without long lead times and production-specific tooling. This paper presents the material system and robotic F3DP setup with two experimental case studies: a perforated facade panel and an arched beam slab. Both cases use concrete as structural material and strategically placed custom-printed foam elements. In this first preliminary study, concrete savings of up to 50% and weight reduction of more than 60% could be achieved. This is competitive with standardized solutions such as hollow-core slabs but, in contrast, allows also for non-standard element geometries. Additional functionality, such as programmed perforation, acoustic absorption, and thermal insulation, could be added through the stay-in-place formwork. Moreover, the challenges and future developments of F3DP for sustainable building processes are discussed. Further studies are required to verify the findings. However, considering the urgent need for resource-efficient, low embodied-carbon solutions in the construction industry, this work is an important contribution to the next generation of high-performance building components.

Features of standard time formation to implement construction processes: a case study

Introduction. The current article is based on the theoretical analysis and experience in the construction processes standardization. The advantages and disadvantages of the existing automated process planning systems (APPS) and the system of computer-aided design and standardization of technological processes SPRUT-TP-Regulation are shown.
 Problem Statement. The existing systems are mainly created for mechanical engineering. The APPS system has also been expanded for the production of metal building structures. However, an issue of the real standard time for construction processes at the construction site remains unresolved. Particular attention is paid to the problem of choosing the structures of formwork systems to optimize the installation of in-situ concrete structures.
 Purpose.Development of a new method for determining the duration and complexity of construction processes that allows to consider any changes in the structure of processes and to determine the standard time by synthesis.
 Materials and methods. The method of integer standardization of processes is considered which, in contrast to existing methods, makes possible to compare the various design solutions of formwork forms.
 Results. The duration of formwork assembly and disassembly is proposed to be determined in whole numbers, depending on the number of formwork elements movements and the degree of responsibility for the reliability and quality of the processes. The article proposes the structure of the construction process and gives the main directions to create an information database regarding the standard time of construction processes implementation.
 Conclusions. The new approach solves the problem of synthesizing the time of construction processes.

Properties of Microconcrete Produced with Fly Ash and Ultrafine Silica

Abstract Microconcrete is an important subclass of regular concrete that lacks the coarse aggregate commonly found in standard concrete. This makes it a good candidate for certain casting operations, such as densely reinforced elements. Microconcrete also tends to have better workability and smoother flow in formwork elements than regular concrete. However, one of humanity’s current problems is air pollution caused by chemical, physical, or biological agents with harmful effects on the environment. Carbon dioxide (CO2) resulting from cement production is a major atmospheric pollutant. To align with sustainable development standards, the construction industry must seek alternative materials that are more environmentally friendly. This article presents a comparison of the properties of regular microconcrete and microconcrete with additives such as fly ash and ultrafine silica. This topic is important because environmental issues are becoming more pressing. The results show that using waste products as additives in microconcrete can provide a sustainable solution for reducing carbon dioxide emissions and environmental impact. Although lower strengths were obtained compared to traditional concrete, microconcrete with waste products can be used in various applications, such as the production of prefabricated construction elements or the rehabilitation of existing structures. Additionally, it can be used in the construction of paving stones, sidewalks, or industrial floors, contributing to reducing pollution and environmental impact.

Adaptive Design of Formworks for Building Renovation Considering the Sustainability of Construction in BIM Environment—Case Study

Progressive technologies and practices are shifting the possibilities of building design and improving work efficiency. Constantly changing site conditions require different procedures and designs that take into account these changing conditions, whether it is a design solution, a change in environmental conditions, or just sustainability factors. Adaptive building design offers opportunities to cope with changing factors to achieve the ähighest possible level of building quality. This case study deals with the topic of adaptive formwork design for building renovation, taking into account sustainability. The aim of the article is an investigation and demonstration of the building information modeling (BIM) environment used for the adaptive design of formwork elements for the building renovation in the context of sustainability. The object of the case study is a building in the center of Kosice, Slovakia. The BIM environment allows prompt and correct adaptation of the formwork design to changing lighting conditions, ventilation, heating and temperature during the design of the building.

Woodworking in the Bronze Age Southern Trans-Urals (the case study of the fortified settlement of Kamenny Ambar)

The paper presents the description and analysis of the collection of wood (formwork elements and objects) from wells of the Bronze Age fortified settlement of Kamenny Ambar (Chelyabinsk Oblast). Within the settlement, presented are the layers of the Sintashta, Petrovka and Srubnaya-Alakul traditions, covering the period of the 21st–17th c. BC. We give a short description of the forest resources of the study area. In Southern Urals, wood can be found in the form of charred remains, sometimes in post holes, in burial structures of various state of preserva-tion, as well as in the Bronze Age wells. The latter has been the source of fragments of formwork and some household items for this study. According to palaeobotanical data, the local landscape represented forests mixed with steppe and forb meadows. The total area of forestlands around the settlement in the Bronze Age was roughly similar to the modern one. The analysis of charcoal and wood from wells indicates that pine (51 %) and birch (47 %) were the most common, and to a lesser extent — willow and alder (2 %). Prevailing were the pine trunks with 5 to 30, less often 50, rings. The types of formwork and tools used in their construction have been determined. The importance of woodworking among the household industries of the settlement has been assessed. Remains of wooden structures have been found on the bottom of 16 examined wells, although there may have been more, judging by discrete fragments of wood decay. The wood is represented by stakes, half-logs, chopping blocks, planks, branches, charcoal and fragments of bark. Restored specimens have been examined visually and using a microscope in order to determine the wood species and process tools, and the results have been put down into the database. In the process of excavation, two types of formwork were identified: 1) a wattle cylinder made of twigs intertwined through vertical stakes, and 2) sheeting of the shaft with vertically placed and tightly fitted boards and/or half-logs of small diameter. In a number of wells, the type of construction could not be accurately determined. In addition to wooden structures, wooden objects were also found at the bottom of several wells. It is possible to state that the inhabitants of the Kamenny Ambar settlement were skilled in wood processing. Available data indicate that carpentry craft was highly developed throughout the entire Bronze Age period. Admittedly, peo-ple knew how to joint wooden parts of structures. Since there are no finds of metal nails, we are confident that they used alternative means, such as ropes and other carpentry techniques, in particular, groove joining. An ob-ject with a precise rectangular groove was found in one of the wells. These materials demonstrate the presence of good engineering knowledge, manifested not only in the search for new technologies for the well construction, but also in the overall architecture of the settlement.

Strength of the monolithic coverings with non-fixable formwork of steel fibro-tuffcrete elements

The article presents the strength study results of the tuffcrete flexible monolithic structures with fixed formwork, combined reinforced rods and fibers. The nature and degree of the fibers percentage influence in the tuffcrete element of the fixed formwork, the dimensions of the fixed formwork elements’ fiber-reinforced section and the strength of monolithic tuffcrete on the normal strength to the longitudinal axis of the monolithic combined-reinforced bending floor structures, as well as on the adhesion strength of the fixed form contact line with concrete monolithic, are analyzed. The experimental dependences that make it possible to more economically design the structures under consideration, taking into account the strength and quantity parameters, as well as the geometric dimensions of their individual components, are proposed.

Construction technology of fixed formwork and quality control

The main results of the research are to find numerical solutions for selecting effective fixed formwork material for columns and analysis of technological operations. The use of fixed formwork of glass-magnesite sheet allows improving quality and stability of the structure, increase fire resistance, which helps to extend the life of the concrete structure.Based on numerical and experimental studies, a model of the formwork fastener for a round column of 3 m high, with a diameter 500 mm was developed. A calculation model was created and the design of the formwork made of glass-magnesite sheet was calculated. So, for the diameter of the concrete column from 300 to 600 mm, the thickness of the glass-magnesite sheet varies in the range: 7-23 mm.A workflow has been developed for the installation of fixed formwork and for concreting columns with the determination of the required amount and type of work, with the determination of the complexity; a workflow for the quality control of work has also been developed. Such periods as: accepting of elements of fixed formwork, installation of fixed formwork elements, accepting of timbering construction operations must be monitored.

Modern technologies of construction of residential and office buildings with removable formwork

The Plastbau and Plastbau-3 systems are mainly used in construction of residential and office buildings. These technologies can be used for construction at low temperatures. The design of wall formwork elements includes the outer and inner layers of polystyrene foam fastened together at the 200 mm distance with a frame made of 3-8 mm reinforcing bars. The systems’ thermal insulation capacity is very high and varies depending on the thickness of polystyrene foam walls. Insulation slabs of the Plastbau-3 formwork panels are made of first class polystyrene foam with a density of 30 kg/m3 and an almost unlimited working life is guaranteed. High efficiency and energy conservation rate embedded in this construction technology and its elements allow to construct high-quality housing at a low cost. Currently, the Plastbau-3 technology is used at construction sites in Moscow, St. Petersburg, Saratov, Orenburg, and other cities.

Perfecting technology of winter concreting of cast-in-situ columns

The article deals with an analysis of the existing systems of the heating method of reinforced concrete structures. It is demonstrated that, concreting of rectangular columns, the area of angles is characterized by a lower concrete quality than in other areas, which causes extensive damage in indicated zones. To remove the existing limitations, the formwork design for concreting of cast-in-situ columns is offered in the article. It was established that during the removal of column formwork one can often observe palled angles with reinforcement uncovering. Corners are the most vulnerable parts under impact forces or static loads during the exploitation. Repair and restoration of the exterior view and protective properties of concrete in column corners often require using materials or repair methods, which increase the cost of construction. The reasons of concrete lower quality are in the incompact joints of formwork elements and the chilled temperature of concrete hardening. Furthermore, the reason is in low temperature in columns corners. It is the consequence of the deficiency of existing heating systems ignores the irregularity of heating proper emission of the heat and increased heat loss in the corners of the columns.

Utilising Building Component Data from BIM for Formwork Planning

Advancements in the computing realm have assisted the Architecture, Engineering, and Construction (AEC) industry to progress significantly by automating several design tasks and activities. Building Information Modelling (BIM) authoring tools have played a significant role in automating design tasks and reducing the efforts required by the designer in redundant, repetitive or production-oriented activities. This paper explores one such approach that, with the help of BIM authoring tool and its Application Programming Interface (API), reduces the efforts expended on formwork design for concrete structures. The paper utilises the concept of using BIM data as input to compute the quantity of formwork, and generate visualisations and schedule of formwork. The developed approach first takes data input from semantic BIM to the API environment for computation and design of formwork systems, which is then placed within the BIM model, to generate visualisation and prepare schedules. The research work utilises a structural concrete wall as an example to demonstrate the presented approach. The approach will be influential in streamlining the formwork design process in the BIM environment and reducing efforts required by the designer and the planning engineer. Since the formwork elements are generated as 3-Dimensional (3D) solids and smart BIM elements, the generated model of formwork can be used for resolving clashes, scheduling, and resource planning.

Flexible fiber-reinforced plastic formworks for the production of curved textile-reinforced concrete

A new constructive and technological approach was developed for the efficient production of large-dimensioned, curved freeform formworks, which allows the manufacturing of single- and double-curved textile-reinforced concrete elements. The approach is based on a flexible, multi-layered formwork system, which consists of glass fiber–reinforced plastic. Using the unusual structural behavior caused by anisotropy, these glass fiber–reinforced plastic formwork elements permit a specific adjustment of defined curvature. The system design of the developed glass fiber–reinforced plastic formwork and the concrete-lightweight-elements with stabilized spacer fabric was examined exhaustively. Prototypical curved freeform surfaces with different curvature radii were designed, numerically computed, and produced. Furthermore, the fabric’s contour accuracy of the fabric was verified, and its integration was adjusted to loads. The developed textile-reinforced concrete had a high three-point bending tensile strength. Beyond that it was ensured that the textile-reinforced concrete had a high durability, which has been shown by the capillary suction of deicing solution and freeze–thaw test with a low amount of scaled material and a relative dynamic E-modulus of 100% after 28 freeze–thaw cycles.

Experimental and Numerical Studies on Flexural Behavior of Ultrahigh-Performance Concrete Panels Reinforced with Embedded Glass Fiber-Reinforced Polymer Grids

The use of glass fiber-reinforced polymer (GFRP) grids in reinforced concrete construction offers several advantages, such as high tensile strength and excellent corrosion resistance. This paper presents the results of experimental and numerical studies of the flexural performance of ultrahigh-performance concrete (UHPC) panels reinforced with GFRP grids. Such panels can be prefabricated and used as permanent formwork elements for bridge columns or walls. The mechanical properties of GFRP grids and UHPC were experimentally evaluated. The flexural performance of panels containing different reinforcement configurations was evaluated in three-point bending tests. The GFRP grids were found to be able to significantly enhance the flexural performance of the UHPC panels. A three-dimensional nonlinear finite element model was established by using ABAQUS, which incorporated the concrete damage plasticity model and can be used to predict the postfracture behaviors. The numerical model was experimentally validated by using the three-point bending test results and was then used for parametric studies. The studied parameters included the panel thickness and the layer number of the GFRP grids reinforcement. The proposed GFRP–UHPC panel system was shown to be promising for the development of lightweight, high-performance permanent formwork. Such formwork can be used in the accelerated construction of critical infrastructures for the enhancement of crack resistance and extension of the service life.

Anisotropic fibre-reinforced plastics as formworks for single and double-curved textile reinforced concrete

A new constructive and technological approach was developed for the efficient production of large-dimensioned, curved freeform formworks, which allows the manufacturing of single and double-curved textile reinforced concrete elements. The approach is based on a flexible, multi-layered formwork system, which consists of glass-fibre reinforced plastic (GFRP). Using the unusual structural behavior caused by anisotropy, these GFRP formwork elements permit a specific adjustment of defined curvature. The system design of the developed GFRP formwork and the concrete-lightweight-elements with stabilized spacer fabric was examined exhaustively. Prototypical curved freeform surfaces with different curvature radii were designed, numerically computed and produced. Furthermore, the fabric’s contour accuracy of the fabric was verified, and its integration was adjusted to loads. The developed textile reinforced concrete (TRC) had 3-point bending tensile strength of 41.51 MPa. Beyond that, it was ensured that the TRC had a high durability, which has been shown by the capillary suction of de-icing solution and freeze thaw test with a total amount of scaled material of 1172 g/m² and a relative dynamic E-Modulus of 100% after 28 freeze-thaw cycles.

Unsymmetrical Fibre-Reinforced Plastics for the Production of Curved Textile Reinforced Concrete Elements

A new constructive and technological approach was developed for the efficient production of large-dimensioned, curved freeform formworks, which allow the manufacturing of single and double-curved textile reinforced concrete elements. The approach is based on a flexible, multi-layered formwork system, which consists of glass-fibre reinforced plastic (GFRP). Using the unusual structural behavior caused by anisotropy, these GFRP formwork elements permit a specific adjustment of defined curvature. The system design of the developed GFRP formwork and the concrete-lightweight-elements with stabilized spacer fabric was examined exhaustively. Prototypical curved freeform surfaces with different curvature radii were designed, numerically computed and produced. Furthermore, the fabric’s contour accuracy of the fabric was verified, and its integration was adjusted to loads.

Innovative Applications of Textile-Based Composites in Strengthening and Seismic Retrofitting as Well as in the Prefabrication of New Structures

The authors review investigations which have provided fundamental knowledge on the use of a new generation of composite materials, namely textile-reinforced mortar (TRM) and textile-reinforced concrete (TRC), as strengthening and seismic retrofitting materials of existing concrete and masonry structures, as well as in the prefabrication of new reinforced concrete (RC) structural elements. In the first part of the paper, TRM are investigated as a means to provide confinement in concrete, to increase the deformation capacity of old-type RC columns subjected to simulated seismic loading, to increase the shear and flexural resistance of RC members and to increase the out-of-plane or in-plane strength of unreinforced masonry walls. In all cases, the effectiveness of TRM systems is quantified through comparison with equivalent fiber-reinforced polymer (FRP) ones. It is concluded that TRM jacketing is an extremely promising new technique, which is expected to enjoy the attention of the research community and to be employed in numerous applications in the near future. In the second part, the paper gives a brief overview of the application of TRC in the field of advanced prefabricated systems, with a focus on stay-in-place (or permanent) formwork elements in hybrid construction projects. Along these lines, the paper provides experimental results on the behavior of TRC/RC composite beams and one-way slabs under flexure. The results indicate that the use of prefabricated TRC stay-in-place formwork elements is a promising solution for achieving reduction of the construction time, minimization of labor cost and defect-free finishing of external surfaces.

Shell Elements of Textile Reinforced Concrete Using Fabric Formwork: A Case Study

Innovations in formwork solutions create new possibilities for architectural concrete constructions. Flexible fabric replaces the stiff traditional formwork elements, and takes away a limiting factor for creative designs. Combined with textile reinforcement, the production of a new range of curved and organic shapes becomes possible without the intensive labour for formwork installation. Besides a general introduction about the concepts of fabric formwork and textile reinforcement, this paper focuses on the production and structural evaluation of doubly curved shells. Creating a very interesting type of element from a structural point of view, the shape flexibility of both the fabric formwork and textile reinforcement make a perfect match to overcome practical production issues for thin shell elements. The application of shotcrete and the integration of non-metallic reinforcement allowed first of all the production of very thin concrete shell elements based on the design approach of the textile architecture. Comparing a shell structure with traditional reinforcement and one with textile reinforcement, a case study evaluates furthermore both the design and the structural performance of such a shell structure.

Development of GFRP-reinforced GFRC for thin permanent formwork applications

A major impediment for the development of precast concrete permanent formwork and other thin structural elements such as cladding is the minimum cover requirement to the reinforcement. For aggressive environments, this can be up to 50 mm, which results in minimum 100 mm thickness units. Currently, glass-fibre-reinforced concrete or cement (GFRC) is used to address that problem in small non-structural elements. However, the structural capacity of GFRC is limited and fibre-reinforced plastic (FRP) reinforcement can be used to structurally reinforce GFRC to enable the development of much larger units. The ‘skin and rib' concept for the design of such units has been developed by the authors and has been used for the design of precast units. The main issues relating to GFRP-reinforced GFRC are bond, anchoring, tension stiffening, deflections and shear capacity of thin panels. This paper presents experimental and analytical work undertaken to address all the above issues. Pull-out tests confirm that the pull-out resistance of FRP is greater in GFRC than in concrete. Flexural capacity and deformations can be predicted provided the tensile properties of the GFRC are determined and modelled correctly. Finally the shear resistance of the elements is examined and design proposals are made. The work demonstrates that it is possible to develop 1 cm thick GFRC permanent formwork for bridge or building applications – spanning unsupported up to 3·85 m and up to 10 m with intermediate supports, thereby providing a durable and economic alternative to metal decks.