Structural Lightweight Concrete
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STRUCTURAL LIGHTWEIGHT WITH EXPANDED CLAY LATERLITE

CONTENTS FOREWORD This publication is intended as a work tool for all those who need further information on structural lightweight concrete prepared with expanded clay. The use of structural lightweight concrete is strongly expanding and the interest in its features is spreading also as concerns ordinary construction works. Hence, we want to summarize the features, the applications, the performances, the standards and the packaging and laying modalities. This publication is especially meant for those who calculate, control and use structural lightweight concrete prepared with expanded clay,...

INTRODUCTION 1. INTRODUCTION: STRUCTURAL LIGHTWEIGHT CONCRETE Structural concrete with Exclay Diagram showing the trends of the strength level according to the density for the various lightweight aggregates. Calcestruzzi leggeri strutturali The Italian legislation currently in force concerning concrete sets forth that “structural lightweight concrete“ can be defined as a concrete aggregate with closed structure obtained replacing in whole or in part the ordinary aggregate with an artificial lightweight aggregate, formed by expanded clay or schists. The possibility of creating lighter...

APPLICATIONS 2. APPLICATIONS OF STRUCTURAL LIGHTWEIGHT CONCRETE The use of lightweight structural concrete has a wide and interesting bibliography ranging from off-shore structures to bridges or large building roofs, but besides being an excellent solution in complex situations it is also a plus in many other cases, closer to the designing and construction activities. 2.1 RESTORATION OF FLOORS In the restoration of wood, corrugated sheet, I-beam and tile floors which calls for a structural concrete to consolidate the floor without overloading the existing structure too much. Wood floors...

Corrugated sheet floors Catholic University - Milan Tertiary sector - Brescia I-beam and tile floors Restoration of floor - Farmstead in Asti Moschino Show Room - Milan Restoration of vaults - Vigevano castle Consolidation of vaults - Bergamo Restoration of tile and cement floors Re-qualification of attics - Milan Shifting of floor in historical building - Como

APPLICATIONS 2.2 RESTORATIONS IN GENERAL Restorations, besides for floors, for all other types of casting (piles, bearing walls, beams, slabs, stairs, structures on shelves, etc.) that have to be lightened up not to weigh on pre-existing structures and foundations. Exclay Structural Concrete. Weldmesh or metal grid. Existing floor or structure to reinforce. Continuous or dotted metal connectors for slab acting compositely with the structure. Restoration of the Vigevano Castle Restoration of the roof of the Loreto 2.3 STRUCTURAL CASTING Structures in which the load is the main component of...

2.4 COSTRUCTIONS IN SEISMIC AREAS The action of the earthquake is proportional to the mass of the structures involved: in constructions in seismic areas lightening a structure means reducing the stress on the outer walls especially in restoration works. 1 Exclay Structural Concrete. 2 Weldmesh or metal grid. Restoration of Alfonsino Castle - Brindisi Port S. Francesco Church, Assisi Panels of an industrial unit - Forlì Concrete roof tiles - Boffalora Ticino 2.5 PREFABRICATED STRUCTURES In prefabricated structures to the beneficial post-tensioning effect, lightness (especially in concrete...

EXPANDED CLAY FOR STRUCTU 3.1 THE PRODUCTIVE CYCLE Expanded clay is a natural aggregate (ANAB certificate – June 2002) obtained by burning particular types of clay in rotating furnaces. After excavation, the clay is left for long periods outside so time, weather and climatic conditions can perform a first natural “pre-preparation” phase. In the second industrial phase, mills crush the clay into very fine particles and prepare it for the furnace. The raw clay is put inside a rotating furnace and burned at increasingly high temperatures. Due to the combined action of gases that develop inside...

JRAL CONCRETE Grain size Compressive strength Thermal conductivity XW/mK EXCLAY STRUCTURAL Grain size Compressive strength EXCLAY TERRECOTTE Grain size Compressive strength EuroclassAI (Incombustible) EuroclassAI (Incombustible) EuroclassAI (Incombustible) "Grain size" does not refer to the diameter of Exclay grains expressed in mm but it is a commercial item The above mentioned density and strenght are average values calculated on the yearly production controls of every production unit, with a ± 15% tolerance as established by the UNI Standard. For more detailed and updated information...

THE STANDARDS 4. THE STANDARDS For many years now Italian legislation has thoroughly and clearly dealt with the issue of structural lightweight concrete. Let’s see which regulations are used today at both international and national level, which are the calculation procedures used and the particularities of lightweight expanded clay concrete. 4.1 INTERNATIONAL TECHNICAL STANDARDS First it might be appropriate to refer to the international standards that include both calculation codes and specific technical regulations for the application of structural lightweight concrete. The ample...

The obligation to design structures in compliance with these regulations and relating technical standards is laid down by Law no. 1086 of February 5, 1971. Both decrees clearly speak about concrete with “ordinary” aggregates, but the Notice of the Ministry of public works of October 15, 199(4) (hereinafter referred to as “Notice ‘96”) gives detailed information, modifications and integrations to the above decrees for concrete aggregates made with lightweight expanded clay aggregates. As concerns the calculation with the admissible tension method, reference is made to the same Notice of the...

LIGHTWEIGHT AGGREGATE Excerpt of “Notice ‘96” … E. Concrete aggregate structures with normal or pre-stressed reinforcements made with artificial lightweight aggregates. The works and elements in cement made with artificial lightweight aggregates as defined in E.1 and with ordinary and/or pre-stressed reinforcements, follow the regulations of ordinary concrete (Technical Standards Part 1 and relating annexes), modified by the following standards. E.1 Structural lightweight concrete Structural lightweight concrete is a concrete aggregate with a closed structure obtained by replacing in whole...