Prediction & optimization of alkali-activated concrete based on the random forest machine learning algorithm

Alkali-activated concrete (AAC) is regarded as a promising alternative construction material to reduce the CO₂ emission induced by Portland cement (PC) concrete. Due to the diversity in raw materials and complexity of reaction mechanisms, a commonly applied design code is still absent to date. This study attempts to directly...

A mix design methodology of blast furnace slag and fly ash-based alkali-activated concrete

Although the application of blast furnace slag and fly ash-based alkali-activated concrete (BFS/FA-AAC) has both economic and environmental benefits, it is limited by the lack of a straightforward mix design method. In this paper, an experiment was conducted to investigate the effect of control factors, including the Na₂O/binder...

Verduurzaming tunnelgietbouw: Beperkte aanpassing, grote impact

Met tunnelgietbouw kunnen snel en tegen lage kosten woningen worden gerealiseerd. Het is dan ook een veel toegepaste bouwmethodiek. Er valt potentieel veel terrein te winnen ten aanzien van milieu-impact door de betonsector.

First-Year Field Performance of Epoxy-Modified Asphalt

Pavement materials containing epoxy-asphalt are mainly used to enhance the fatigue cracking resistance of surfacing layers on bridges. These materials have also been proposed for roadways, but limited field data are available. In this research, a fully instrumented epoxy-modified asphalt surfacing layer was applied to measure strain responses in...

A mix design methodology of slag and fly ash-based alkali-activated paste

In this paper, a series of experiments were conducted to systematically and quantitively explore the effects of control factors on the early age properties, i.e., workability and strength of slag and fly ash-based alkali-activated paste (BFS/FA-AAP). The control factors on the workability (flowability and setting time) of BFS/FA-AAP include...

Use of fine recycled concrete aggregates in concrete: A critical review

This paper discusses the state-of-the-art of the fine recycled concrete aggregates (fRCA), focusing on their physical and chemical properties, engineering properties and durability of concretes with fRCA. Based on the systematic review of the published literature, it is impossible to deduce without any further research the guidelines and...

Review of warm mix rubberized asphalt concrete: Towards a sustainable paving technology

In recent years, transportation agencies and the general public alike are demanding increased considerations of sustainability in transport infrastructure. Warm mix asphalt (WMA) is developed for reducing energy consumptions and emissions in asphalt paving industry. In addition, the use of rubberized asphalt concrete (RAC) has proven to be...

Design considerations and sustainability of self-compacting concrete

Strength development of concrete: balancing production requirements and ecological impact

The effective production of concrete structures requires adequate control of<br/>strength development in order to realise the scheduled production cycles. Demoulding of elements can take place only when sufficient strength is gained and the production cycle has to be maintained with seasonal changes of temperature. The use of Portland Cement...

Design of concrete for high flowability: Progress report of fib task group 4.3

Flowable concretes can differ significantly from traditional vibrated concrete. Concrete types like selfcompacting concrete (SCC), ultra-high performance concrete (UHPC) and high performance fibre reinforced cementitious composites (HPFRCCs) require novel mix design approaches. This has consequences for the production and the performance in the...

A performance -based method for granular based method for granular -paste mix design

In this paper a performance-based method for the design of granular-paste mixtures will be proposed. Focus will be on the selection and proportioning of constituents to produce a mixture with a pre-defined shape holding ability. Shape holding ability of mixtures will be characterized by the shape preservation factor SPF. This SPF shows the...

American and European Mix Design Approaches Combined: Use of NCHRP Performance Indicators to Analyze Comité Européen de Normalisation Test Results

This paper describes a project that is part of NL-LAB, a larger, long-term program at Delft University of Technology, Netherlands, which aims to establish the predictive capacity of the current European functional tests for Dutch asphalt concrete (AC) mixtures. In this NL-LAB program, the functional characteristics of resistance to rutting (EN...

Historic Concrete: From Concrete Repair to Concrete Conservation

Concrete like materials were already applied during the Roman Empire. After the decline of the Roman Empire, a wide scale application of concrete only reappeared in the 19th century. Here lies also the origin of modern (reinforced) concrete. Since then, both concrete application and composition have significantly changed. Today, concrete from...

Shape, sizing optimization and material selection based on mixed variables and genetic algorithm

In this work, we explore simultaneous designs of materials selection and structural optimization. As the material selection turns out to be a discrete process that finds the optimal distribution of materials over the design domain, it cannot be performed with common gradient-based optimization methods. In this paper, material selection is...

LOT, a meso scale mechanistic tool for Porous Asphalt mixture design; winter damage and LOT validation

By assignment of the Centre for Transport and Navigation (DVS) of the Dutch Ministry of Transport, Public Works and Water Management the Delft University of Technology developed LOT. LOT is a Lifetime Optimisation Tool for Porous Asphalt, PA, based on meso scale structural modelling. LOT sees an asphalt mixture as a structure and computes stress...

Single Fibre Pullout from Hybrid Fiber Reinforced Concrete

Hybrid fiber reinforcement can be very efficient for improving the tensile response of the composite. In such materials, fibers of different geometries can act as bridging mechanisms over cracks of different widths. The fiber bridging efficiency depends on the interface properties, which makes interface characterization very important. Therefore...

Self-compacting fibre-reinforced concrete

The project 'self-compacting fibre-reinforced concrete (SCFRC)' is part of the Dutch STW/PPM program - 'cement-bonded materials' - DCT.4010. Subproject III to which the project ,SCFRC' belongs deals with the development of new high performance concretes. The project 'SCFRC' aims at investigating the effect of type and content of fibres on the...

Single fiber pullout from hybrid fiber reinforced concrete

Hybrid fiber reinforcement can be very efficient for improving the tensile response of the composite. In such materials, fibers of different geometries can act as bridging mechanisms over cracks of different widths. The fiber bridging efficiency depends on the interface properties, which makes interface characterization very important. Therefore...