The Effect of Admixtures on the Buildability of 3D Printed Alkali-Activated Materials with Glass Wool: 3D Printing of Alkali-Activated Materials

Research about alkali-activated materials or geopolymers has increased in the past decade as they are regarded as a potential replacement to cement-based materials. This is due to the fact that alkali-activated materials possess several advantages over cement-based materials, and the most important one is that they are more sustainable to the...

Evaluation of material properties of hot mix asphalt mixtures with high levels of reclaimed asphalt pavement using multi-scale characterization

Because of the sustainability transition in the asphalt industry, it is increasingly popular to apply reclaimed asphalt pavement (RAP) instead of new asphalt. Then, less new material is needed and the amount of waste products is reduced. However, there are questions regarding the performance of asphalt mixtures with high RAP percentages,...

Numerical study on the creep behaviour of Fiber-Reinforced Polymer sandwich structures considering traffic loading

Ageing of infrastructure leads to an increasing demand for new technologies and design solutions in current bridge engineering. Over the last decades the traffic intensity has grown tremendously, while design codes and regulations have become stricter. Many current steel bridges realised in The Netherlands suffer from fatigue problems....

Closed-form solution for the buckling analysis of Euler-Bernoulli columns and beam-columns with jump discontinuities: The influence of step-changes of geometrical and material properties, real joints, non-propagating open edge cracks, and real support conditions

Structural elements under compression can fail due to instability. Such type of failure may present itself as flexural buckling, which is the sudden change of configuration of one state to another at a critical compressive load. Actual structure characteristics, such as cracks, real joints, sudden changes of flexural stiffness, bracing, and...

Experimental investigation of concrete mixtures incorporating recycled concrete aggregates

In the Netherlands, yearly 33 Mton new concrete (roughly 15 billion m3) is producewhile 12 Mton concrete waste becomes available. Recycling of the yearly 12 Mton concrete waste results in roughly 7 Mton coarse recycled concrete aggregate (CRCA) and 5 Mton fine recycled concrete aggregates (fRCA). Currently, fRCA is not used in structural...

Control of early-age cracking aimed at a test case for bacterial self-healing concrete

Since 2006, the Delft University of Technology has been working on the development of bacterial self-healing concrete (BSHC). The self-healing ability of this concrete is based on a biological mechanism, in which mineral producing bacteria are added to repair cracks autonomously. This not only improves the durability of concrete structures, but...

3D Concrete Printing: The influence of printing process parameters on the mechanical properties, numerical modelling, and the exploration of sustainable printable solutions for humanitarian problems

Concrete is one of the most widely applied construction materials worldwide. Although traditional construction processes are optimized in terms of efficiency, costs and material use, the main disadvantages are still related to the use of formwork, labour and limited freedom of shapes in architectural design. The future of concrete structures...

Alkali silica reaction in the afsluitdijk: Assessment of concrete damage and remaining service life using experimental and modelling research

Alkali Silica Reaction (ASR) is one of the degradation mechanisms in concrete that poses a threat to the service life of existing structures. This physio-chemical process is progressive and can affect the the strength, stiffness and stability of concrete structures. A lot of mitigation measures are available to prevent the deleterious effects of...