Determining a functional responsibility allocation between public and private parties in a long-term maintenance contract for waterworks

A proper allocation of risks and responsibilities is vital for the success of long-term maintenance contracts. This paper focuses on a method to identify an adequate allocation of responsibilities for the maintenance of waterworks. The Dutch agency recently started outsourcing the maintenance of their waterworks in DBFM contracts. In order to...

Common misunderstandings in life cycle costing analyses and how to avoid them

LCC analyses (LCCA) and discounting calculations are applied by public sector organizations in the Netherlands. Still numerous misunderstandings can be recognized. An overview is given of some common misunderstandings found in Life Cycle Costing Analyses. Issues relating to public assets are: the absence of residual value, long life cycles, high...

Use of a future maintenance demand indicator for network level asset management decision making

This paper discusses the development and first testing of a valid, reliable, functional and simple indicator, that represents the long term effect of short term decisions. Such an indicator can assist counteracting short term views in network level asset management decision making. Short-termism or myopia may occur in cases where service level...

Experimental study on pore connectivity and its influence on chloride transport in saturated cementitious system

The purpose of this paper is to investigate the pore connectivity and its influence on chloride transport property in cementitious materials under saturated condition. Mercury intrusion porosimetry experiment was carried out on a variety of hydrated cement pastes curing up to one year. By repeating pressurization-depressurization cycles, pore...

Microstructural and Mineralogical Analysis of Alkali Activated Fly Ash-Slag Pastes

The performances of alkali activated materials (AAM) are strongly related to their microstructures. The microstructure development is mainly affected by chemistry of the primary raw materials. In the present study the influence of different proportions of fly ash and slag (100:0, 70:30, 50:50, 30:70, 0:100 wt.%, named S0, S30, S50, S70, S100,...

Reaction Kinetics and Thermodynamic Modeling of Sodium Hydroxide Activated Slag Paste

The technology of alkaline activation of calcium aluminosilicate materials, as an alternative to Portland cement to produce a clinker-free material, can address the energy and environmental concerns associated with Portland cement production. As this technology attracts more and more attention in recent years, there are increasing researches...

Verification of joint input-state estimation by means of a full scale experiment on a footbridge

This paper presents a verification of a state-of-the-art joint input-state estimation algorithm using data obtained from in situ experiments on a footbridge. A dynamic model of the footbridge is based on <br/>a detailed finite element model that is calibrated using a set of experimental modal characteristics. The joint input-state estimation...

A comparison of two Kalman-type filters for robust extrapolation of offshore wind turbine support structure response

Quasi-periodic loading resulting from waves and a rotationally sampled wind field often leads to fatiguedriven designs for offshore wind turbine support structures. The uncertainty on wind and wave loading, together with large modelling uncertainties, lead to large discrepancies between the observed and predicted dynamic behaviour of these...

Development of Stop Criteria for Proof Loading

Proof loading of bridges is an option to study existing bridges when crucial information is lacking. When proof loading is chosen, the question arises which maximum load should be attained during the test to demonstrate sufficient capacity, and which criteria, the “stop criteria”, based on the measurements during the test, would indicate that...

Expert judgment in life-cycle degradation and maintenance modelling for steel bridges

Markov-based models for predicting deterioration for civil infrastructures are widely recognized as suitable tools addressing this mechanism. The objective of this paper is to provide insights regarding a network of orthotropic steel bridges in terms of degradation. Consequently, a model combining a dynamic Bayesian network and a Markov chain is...