Robert Mark Lawson

This paper presents the results of shear tests on light steel walls with two types of higher specification OSB/3 board and comparison with elastic theory based on the fixing shear stiffness. The tests were performed to BS EN 594 and showed that the design shear resistance was determined as 5.1 kN/m wall length for a limiting deflection of 0.003H or...

This paper addresses the potential use of composite construction in light steel framing in the form of composite columns and walls. It presents the results of tests on composite columns using perforated cold formed steel C-sections to form 100 × 100 mm cross-section columns. Three forms of tests were performed: Short column, long column tests and p...

The performance of a newly developed back pass non-perforated unglazed solar air collector (BPSC) is investigated in this paper for its thermal efficiency. BPSC is a cost-effective solar panel for new commercial buildings and industrial facades, which can be used as a main building wall or for the retrofitting of old buildings. BPSC provides a preh...

This paper explores the concept of the optimum span to depth ratio of reusable composite beams with demountable bolted shear connectors so that the beams may be designed most efficiently in terms of their weight and the shear connector distribution along the span. Three patterns of shear connectors were evaluated by a simple pseudo-plastic model an...

The composite behaviour of fixings acting in shear between gypsum board and thin steel sections depends on the effective properties of the board material in compression at the base of the fixing and the contribution of the head of the fixing as it rotates. An elastic method is presented to determine the stiffness of the fixings, which uses the effe...

A new form of light steel composite beam has been developed that uses C sections acting in tension with shear connectors in the form of screws or bolts or perforations in the web of the C section. The shear and bending resistance is also increased by using side C sections to the beams. Bending tests on point-loaded beams of 0.8, 1.1 and 1.7 m span...

In light steel framing, the compression resistance of the walls may be improved by the stabilising effect of plasterboard attached to one or both sides of the wall. This paper presents the results of 28 load tests on 2·4 m high walls using 75, 100 and 150 mm deep C-sections in 1·2 to 1·6 mm thick steel with various types of board. The results were...

The deflection of steel beams with circular openings is dependent on the loss of bending stiffness and shear area of the web, which adds to the deflection of the solid web beam. The additional deflection is a function of the ratio of opening diameter, ho, to section depth, h, and also of the spacing of the openings. This paper presents derived form...

In this paper, the strength and stiffness of different roof panels were investigated, in order to establish their ability to act as in-plane diaphragms for stressed skin design of cold-formed steel portal frames. A total of 6 roof panels, approximately 3 x 3m, were examined by testing with sheeting profiles fixed on 4 sides. A variety of sheeting p...

The shear resistance and flexibility of a steel roof diaphragm depend largely on shear resistance and slip flexibility of the single screw lap joint. In this paper, screw connections relevant to modern roof construction are investigated. The tests provided experimental values of shear/tearing resistance and joint flexibility of seam connections, cl...

For composite cellular beams, additional deflections occur due to the loss of bending and shear stiffness at the opening positions and also due to slip in the shear connectors caused by partial shear connection. Design formulae are presented for the additional deflection of composite beams with circular openings or for cellular beams as a function...

Composite floors are often used in building construction where beams typically span from 6 to 18 m. They are commonly used together with decking of 50 to 80 mm depth that spans 3 to 4.5 m between the beams. Rules for the minimum degree of shear connection in composite beams are presented in Eurocode 4 and other international Codes, and were derived...

Beams with regular circular web openings (cellular beams) are often used in composite construction. Rules for the minimum degree of shear connection in composite beams are presented in Eurocode 4 but were derived for solid web beams in propped construction. This paper investigates the degree of shear connection requirements for composite cellular b...

This paper presents the basis for the design of steel and composite beams with large web openings. The main design requirements are the transfer of shear by Vierendeel bending and the control of web buckling next to and between the openings. Cellular beams with regular circular openings are a common example of highly perforated beams and their flan...

This paper presents the results of 20 push-out tests on shear stud connectors, placed centrally in the ribs of 58 mm and 80 mm deep steel decking. The tests were designed to investigate the realistic load–slip behaviour of the shear connectors and the influence of transverse loading. The tests considered two different stud diameters and the effect...

The use of steel–concrete composite beams in which wide-flanged steel beams act compositely with a concrete or steel–concrete composite slab above is well established in building construction. However, for composite beams with low degrees of shear connection between the beam and slab, significant additional deflections can occur due to slip in the...

This paper describes a sequence of experiments on a long-span asymmetric composite cellular beam. This type of beam has become very popular, combining the composite action between the steel and concrete with the increased section depth, compared with more commonly used solid-web I sections. Openings in the steel web also reduce the self-weight and...

This paper presents the results of push-out test specimens on shear connectors for composite beams, which are placed centrally in the ribs of novel formed deep steel decking. These deck shapes have not been well considered in the development and the calibration studies of EN 1994-1-1. The presented tests have been designed to investigate the additi...

This paper describes a series of six full-scale laboratory tests conducted on cold-formed steel portal frame buildings in order to investigate the effects of joint flexibility and stressed skin diaphragm action. The frames used for the laboratory tests were of 6 m span, 3 m height, 10° pitch and the frame spacing was 3. m. Vertical loading was appl...

Summary This paper addresses the design of stainless steel sections with large circular openings subject to shear and bending. A total of nine tests on pairs of C sections using 2 and 3 mm thick stainless steel in austenitic 1.4301 and lean duplex 1.4162 grades was performed. The tests showed that the shear resistance at an opening is controlled by...

This paper describes a stressed-skin diaphragm approach to the optimal design of the internal frame of a cold-formed steel portal framing system, in conjunction with the effect of semi-rigid joints. Both ultimate and serviceability limit states are considered. Wind load combinations are included. The designs are optimized using a real-coded niching...

This article reviews the performance characteristics of and some recent developments in slim-floor and integrated beam construction. This form of construction provides a flat floor using precast concrete slabs or deep composite decking and offers advantages over other forms of construction in many sectors. Composite slim-floor beams have superior s...

For small to modest frame spans, cold-formed steel portal frames are a popular and efficient form of construction which can be used for low-rise commercial, light industrial and agricultural buildings. Such buildings are lightweight, have ease of installation and erection, as well as economy. However, in cold-formed steel portal framing systems, th...

Composite beams with highly asymmetric steel sections and large web openings are often found in building structures. It is also recognised that current requirements in EN 1994-1-1 [1] for minimum degree of shear connection of composite beams with highly asymmetric steel sections are significantly more onerous to those for composite beams with symme...

The push-out test as proposed in EN 1994-1-1 originally was developed for solid slabs and not for composite slabs with additional steel sheeting. It leads to a load-slip behaviour of headed shear stud connectors which differs from the behaviour in the real beam. In particular, the vertical forces and negative bending moments of the composite slab a...

Transpired solar collectors (TSCs) are an elegantly simple, facade-integrated solar air-heating technology that is widely used to pre-heat the ventilation air supply of buildings. TSCs have historically been manufactured from long profiled pre-finished steel cladding sheets and used on industrial buildings, with which they are aesthetically compati...

Objective: Thermal building simulation tools take account of the thermal capacity of the walls and floors by a one-dimensional characterization. The objective was to obtain thermal equivalent parameters for ribbed or composite slab elements that can be input into one-dimensional models. Method: Transient finite element calculations (FEM) were used...

Composite beams with large web openings are often used, and their design is controlled by Vierendeel bending at the four corners of each opening, which is assisted by local composite action with the floor slab. Development of this Vierendeel bending resistance may be limited by pull-out failure of the shear connectors.In this paper, a non-linear el...

A design method for continuous profiled decking based on post-elastic moment re-distribution is presented. This method is based on that permitted in EN 1993-1-3: Eurocode 3, and in this paper, its application to highly stiffened composite deck profiles is explored. The new aspect is the way in which the residual negative bending moment is establish...

The thermal efficiency is investigated of the new Kingspan back pass non-perforated unglazed solar collector (BPSC). This technology incorporated into the building sector, can potentially change the role of the building envelope from passive energy conservation, to that of producer of energy. BPSC can be used as a preheated air source for heating a...

Modular construction is widely used in Europe for multi-story residential buildings. A review of modular technologies is presented, which shows how the basic cellular approach in modular construction may be applied to a wide range of building forms and heights. Case studies on 12-, 17-, and 25-story modular buildings give design and constructional...

The elasto-plastic analysis of composite beams is important when considering the increase in bending resistance of the beam and the end slip between the steel and concrete at higher strains. This paper provides a simplified method of elasto-plastic analysis by considering equilibrium of the composite cross-section as a function of its strain profil...

Modular construction is widely used for residential buildings of 4 to 8 storeys. In the context of open building systems, modular construction provides a systemised approach to design in which the benefits of prefabrication are maximised. There is demand to extend this form of construction to more than 12 storeys for residential buildings. This pap...

This publication provides guidance on determining the design resistance of composite beams with large web openings. The composite beams comprise steel I sections with either regular or isolated openings and with a concrete slab on the top flange, connected to the steel section by shear studs. The scope covers rolled steel sections with openings cut...

This publication provides guidance on determining the design resistance of composite beams with large web openings. The composite beams comprise steel I sections with either regular or isolated openings and with a concrete slab on the top flange, connected to the steel section by shear studs. The scope covers rolled steel sections with openings cut...

Modular construction is widely used for residential buildings of four to eight storeys and there is pressure to extend this relatively new form of construction to 12 storeys or more. This paper reviews recent modular technologies, and also presents load tests and the analysis of light steel modular walls in compression. A design method for high-ris...

This paper presents a summary and analysis of research findings on the durability of galvanised cold-formed steel sections used in housing in order to deduce their design life. These cold-formed sections are produced from pregalvanised strip steel. It reviews reports and publications from research projects carried out by Corus and the Steel Constru...

In this paper, the strength and stiffness of different roof structures has been investigated, in order to establish their ability to act as in-plane diaphragms for stressed skin design. In each test setup , a roof panel of approximately 3m x 3m was constructed using top-hat purlins and standard sheeting profiles or composite panels. Different types...

Cold-formed steel sections are often designed and built to act compositely with other constructional materials, particularly with wood and cementitious materials in order to improve their structural performance. This paper reviews some recent developments in composite applications of cold-formed steel sections in the U.K., and presents a number of...

Modern methods of construction (MMC) are defined as those which are highly pre-fabricated and which achieve tangible benefits to the client in terms of speed of construction, higher quality and more efficient and adaptable space use. There are many examples of MMC in light steel framing and modular construction, which are targeted on the residentia...

Light steel construction is often designed to maximise the benefits of interactions with other materials and this paper reviews examples of composite applications of light steel components in flooring and roofing. New forms of steel-timber composite 'plyweb' floor joists and 'open' roofing systems, and steel-gypsum composite floor joists are invest...

The design of composite asymmetric cellular beams is not fully covered by existing guidance but is an area of important practical application. Asymmetry in the shape of the cross-section of cellular beams causes development of additional bending moments in the web-posts between closely placed openings. Furthermore, the development of local composit...

Precast concrete floors are widely used in building construction, but there is little detailed design guidance on their application in steel-framed buildings. Traditionally the steel beams have been designed to support the precast slabs on their top flange. However, there are an increasing number of composite frames and slim floor constructions whe...

This paper describes recent developments in composite construction and their effect on codified design procedures in the UK. Areas of particular interest include: rules on shear connection, design of beams with web openings, serviceability limits, such as floor vibrations, and fire safe design. The design of cellular beams with regular circular ope...

This paper reviews recent developments in pre-fabricated construction systems using light steel and modular technologies, and describes the economic context in which the use of these systems has expanded. Examples of recent important projects using these technologies are illustrated. Hybrid or mixed construction systems have been developed which op...

This publication provides guidance on the design of steel beams acting compositely with precast concrete slabs in multi-storey buildings. The use of hollow core or solid plank precast units offer benefits in terms of cost (the long spanning capabilities of the precast slabs lead to fewer secondary beams) as well as the advantages offered by composi...

The design of long-span composite floors, for office applications, is often controlled by serviceability considerations, particularly occupant induced vibrations. In 1989, the Steel Construction Institute (SCI) published a guide, which presents a design methodology particularly suited to hand methods of analysis. Buildings designed using this guide...

The development of light steel construction in housing in the UK as part of a pan-European funded project `Steel in the Urban Habitat' is reviewed. A demonstration building was constructed at Oxford Brookes University and consisted of a connected four-bedroom house and six-room apartment building. High levels of thermal insulation were incorporated...

Over-cladding of existing buildings concerns the addition of a new facade comprising an independent sub-frame and new cladding which is attached to the original facade. The use of light steel construction in this application is discussed, and the design criteria for over-cladding systems is addressed. Case studies from Denmark, Finland and the UK d...

The renovation of buildings is an important sector of activity, and opportunities exist for the greater use of light steel construction. This publication is aimed at designers and specifiers involved in building renovation, and concerns the use of light steel construction in over-cladding applications.

This paper reviews the design criteria for composite slabs at the fire limit state in accordance with Eurocode 4 Part 1.2 and with other modern Codes. A review of fire test data is presented and an assessment is made of the requirements of EC 4 Part 1.2 relative to these tests. Simplified fire design tables are presented.

There has been considerable interest in many parts of Europe in developing and designing shallow floor systems for use in steel-framed buildings. This form of construction creates a flat floor in which steel beams are contained within the depth occupied by the floor. Shallow floors therefore achieve the minimum depth of construction and, by virtue...

Synopsis The paper summarises the results of three load tests on composite beams of IOm span, comprising one control composite beam (i.e. without opening) and five rectangular openings of various sizes and locations. The tests were carried out under simulated uniform load and were taken to failure of the beam at each opening. The results of the tes...

The stability of I-beams over which a trapezoidal plate is placed, filled with concrete, to form a deck surface, has been investigated by experimental and numerical methods. A method is proposed for approximate determination of deflection and ultimate dynamic loads.

Formulas are presented for the design of folded plate roofs using profiled steel sheeting and standard fastenings, based on their known performance in shear. As a result of full-scale tests to failure, the folded plate design criteria have been identified and evaluated. Consequently, simple expressions are derived for the roof span limitation, whic...

In the stressed-skin analysis of metal structures it is vital to have a simple yet accurate treatment of the shear deformation of profiled metal sheeting. A suitable theory is developed in this paper for the two important cases of sheeting fastened to the supporting structure through every and alternate troughs of the corrugations. Various practica...