Lupita Sierra-Beltran

Delft University of Technology | TU · Department of Structural Engineering

In this chapter an overview will be given of the biotechnological possibilities for repair of concrete with focus on application of limestone-producing bacteria and the different metabolic pathways involved, e.g., via hydrolysis of urea and heterotrophic CO2 production under alkaline conditions. The first paragraph comprises an overview of previous...

Cracks are intrinsic concrete characteristics. However, cracking can endanger the durability of a structure, because it eases the ingress of aggressive gasses and liquids. Traditional practices tackle the problem by applying manual repair. Scientists inspired by nature have created self-healing concrete able to self-repair as a result of the metabo...

Concrete cracks due to several reasons and through the cracks oxygen, water, chlorides and other aggressive agents can penetrate, decreasing the concrete durability, performance and life span. Even though concrete has autogenic capacity to heal the cracks, the size of the cracks that can undergo autogenous healing depends on the exposure conditions...

Zementgebundene Hochleistungsfaserverbundwerkstoffe (engl. High Performance Fiber Reinforced Cement Composites, HPFRCC) stellen eine Klasse von Zementkompositen dar, die dehnungsverfestigend sind, eine hohe Bruchdehnung aufweisen und vor Erreichen der Höchstlast zahlreiche Risse zeigen. Neben dieser mechanischen Definition können weitere Merkmale H...

The paper describes mechanical properties, self-healing capacity and bonding behaviour of a sustainable bio-based mortar repair system for concrete. Two different mixes of strain-hardening cement-based composites (SHCC) have been used. The bio-based agent added to the SHCC consists of both bacteria and food for the bacteria. The metabolic activity...

Different kind of fibres are used as reinforcement for cement based materials. They can increase the mechanical properties of the material and result in higher strength and/or strain capacity. This paper discusses various aspects of applying fibres at different scales. A lattice type model is first described which is used to investigate the behavio...

Every year, there is a demand of more than 110 million metric tons of asphalt all around the world. This represents a huge amount of money and energy, from which a good part is for the preservation and renovation of the existing pavements. The problem of asphalt is that it oxidizes with time and therefore its beneficial properties disappear. Tradit...

Nowadays limestone powder and blast furnace slag (BFS) are widely used in concrete as blended materials in cement. The replacement of Portland cement by limestone powder and BFS can lower the cost and enhance the greenness of concrete, since the production of these two materials needs less energy and causes less CO 2 emission than Portland cement....

This paper highlights the potential of wood fibres as reinforcement for cementitious materials for structural applications. Wood is a natural and renewable resource and only low amounts of energy are required to produce fibres compared to the amounts of energy necessary to produce the artificial fibres currently used as reinforcement. This includes...

This paper presents a model to simulate fracture of fibre reinforced cement based materials. The model is based on a lattice-type fracture model. Fibres are explicitly implemented as separate elements connected to the cement matrix via special interface elements. With the model multiple cracking and ductile global behaviour are simulated of the com...

When a brittle cement matrix is reinforced with fibres the composite's toughness improves and a ductile behaviour could be developed. Wood fibres are currently being studied as a less energy-intensive alternative to synthetic fibres that have been successfully applied in reinforcing cementitious materials. In order to maximize the potential of wood...

This paper presents a model to simulate fracture of fibre reinforced cement based materials. The model is based on a lattice-type fracture model. Fibres are explicitly implemented as separate elements connected to the cement matrix via special interface elements. With the model multiple cracking and ductile global behaviour are simulated of the com...

In this paper a model is presented to simulate fracture of fibre reinforced cement based materials. The model is based on a lattice-type fracture model. Fibres are explicitly implemented as separate elements connected to the cement matrix via special interface elements. With the model multiple cracking and ductile global behaviour are simulated of...

In this paper a micromechanics-based design is proposed for the development of a material with enhanced ductility and flexural strength combined with low production cost. The composite performance is described by 11 micromechanical properties of the system consisting of cement matrix, fibres and fibre-matrix interface. Most of these properties are...