Samenvatting
There is increasing demand from the design society for structures with expressive qualities yet with optimal structural behaviour and material use. For concrete structures the use of structurally curved elements can provide a better design. Curved elements, designed to experience mainly membrane action, are stronger, stiffer and more efficient than straight-lined elements in bending.
The construction of curved concrete surfaces remains however a challenge. The existing formwork method are often complex, costly or material wasting. A second issue hindering the construction is the tensile reinforcement. Reinforcement is always needed in structural concrete elements, but the inflexibility of traditional steel reinforcement practically limits the curvature of structural surfaces.
There is a need for an inventive formwork solution that on the one hand provides the flexibility to obtain curved surfaces and on the other hand has a sufficient stiffness in casting stage, and that can moreover fulfil a reinforcing function. During my research a new method that complies with these criteria is developed by exploiting the properties of textile reinforced cement composites.
Textile reinforced cement composites - TRC - consist of continuous fibre systems, called textiles, which are impregnated with a cement or fine grained mortar. They harden at ambient temperatures. TRC composites are flexible in the wet phase; hence curved shapes can easily be obtained. In hardened phase, they are stiff and strong in both tension (up to 60 MPa) and compression (60 MPa), so they can function very easy as (permanent) formwork with reinforcing properties.
The research focusses on both TRC as a formwork and TRC as reinforcement in the mixed section. Every step is structurally analysed and validated with experimental tests on scale models. This leads to complete the design of curved concrete elements with TRC formwork/reinforcement.
The construction of curved concrete surfaces remains however a challenge. The existing formwork method are often complex, costly or material wasting. A second issue hindering the construction is the tensile reinforcement. Reinforcement is always needed in structural concrete elements, but the inflexibility of traditional steel reinforcement practically limits the curvature of structural surfaces.
There is a need for an inventive formwork solution that on the one hand provides the flexibility to obtain curved surfaces and on the other hand has a sufficient stiffness in casting stage, and that can moreover fulfil a reinforcing function. During my research a new method that complies with these criteria is developed by exploiting the properties of textile reinforced cement composites.
Textile reinforced cement composites - TRC - consist of continuous fibre systems, called textiles, which are impregnated with a cement or fine grained mortar. They harden at ambient temperatures. TRC composites are flexible in the wet phase; hence curved shapes can easily be obtained. In hardened phase, they are stiff and strong in both tension (up to 60 MPa) and compression (60 MPa), so they can function very easy as (permanent) formwork with reinforcing properties.
The research focusses on both TRC as a formwork and TRC as reinforcement in the mixed section. Every step is structurally analysed and validated with experimental tests on scale models. This leads to complete the design of curved concrete elements with TRC formwork/reinforcement.
Originele taal-2 | English |
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Titel | VUB PhD Research Day 2013 (Program and Abstracts) |
Status | Published - 2013 |