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Articles 1 - 11 of 11
Full-Text Articles in Engineering
The Influence Of Different European Cements On The Transport And Early-Age Properties Of Concrete In The Cover-Zone, Niall Holmes, L. Basheer, S. Nanukuttan, Pam. Basheer, W. J. Carter, T. M. Chrisp, G. Starrs
The Influence Of Different European Cements On The Transport And Early-Age Properties Of Concrete In The Cover-Zone, Niall Holmes, L. Basheer, S. Nanukuttan, Pam. Basheer, W. J. Carter, T. M. Chrisp, G. Starrs
Conference papers
The use of in situ tests for performance based specification would require demonstration of their suitability to distinguish the quality of concrete. With the introduction of new European Standards for cements, this would mean concretes produced with these new cements should be classified for their quality using the performance tests. It is generally believed that transport properties of concrete are related to their durability and hence the measurement of these properties can form the basis of performance based specifications. This paper reports data indicating that transport properties measured at 28-days for concretes manufactured with different European cements and water-binder ratios …
Peat Improvement Under Vacuum Preloading:A Novel Approach For Bog Roads In Ireland, Juan Pablo Osorio, Eric R. Farrell, Brendan C. O'Kelly
Peat Improvement Under Vacuum Preloading:A Novel Approach For Bog Roads In Ireland, Juan Pablo Osorio, Eric R. Farrell, Brendan C. O'Kelly
Conference papers
This paper presents the preliminary findings of a TCD/NRA vacuum preloading field trial that is part of a research project into the construction options for improving rampart roads. Vacuum preloading is a construction method used to accelerate settlement and the increase shear strength by applying a vacuum pressure to the ground by means of prefabricated vertical drains, an impervious tight sheet and a vacuum pump. Consolidating the ground by applying a vacuum load has several advantages over other techniques, for example; no fill material is required; construction periods are generally shorter; and there is no need for chemical admixtures. This …
Methodology For Designing Structures To Withstand Extreme Environments: Performance Based Specifications, S. Nanukuttan, Niall Holmes, S. Srinivasan, L. Basheer, P.A.M. Basheer, L. Tang, J. Mccarter
Methodology For Designing Structures To Withstand Extreme Environments: Performance Based Specifications, S. Nanukuttan, Niall Holmes, S. Srinivasan, L. Basheer, P.A.M. Basheer, L. Tang, J. Mccarter
Conference papers
Existing guidelines in BS 8500 allow the selection of concrete mix based on variables such as compressive strength, maximum water to binder ratio, minimum cement content and minimum cover thickness. This approach does not guarantee the durability and expected performance of the concrete structure in a given environment. One alternative is to develop performance- based specifications that supplement the existing guidelines in BS 8500, by specifying the required performance of concrete in terms of measurable properties such as resistance to environmental penetrations. This paper demonstrates one of such methodology for developing performance-based specifications for concretes exposed to marine environments. Chloride …
Development Of A New Marine Exposure Site On The Atlantic North-West Coast Of Ireland, Niall Holmes, L. Basheer, S. Nanukuttan, S. Srinivasan, Pam Basheer, J. Mccarter, M. Chrisp
Development Of A New Marine Exposure Site On The Atlantic North-West Coast Of Ireland, Niall Holmes, L. Basheer, S. Nanukuttan, S. Srinivasan, Pam Basheer, J. Mccarter, M. Chrisp
Conference papers
This paper presents a new marine exposure site being developed on the North-west Atlantic coastline of Ireland in Co. Donegal by the Centre for Built Environment Research at Queen’s University Belfast. The site will initially contain a number of large precast concrete stems, each 1.5m high, 1.5m wide and 1m thick placed on concrete plinths poured in-situ. The concrete stems will be placed at three levels to achieve different exposure conditions outlined in EN 206, namely atmospheric (XS1), a splash or spray zone (XS3) and a tidal zone (XS3) where the stems will be submerged by the incoming tide twice …
Developments In Intelligent Monitoring Of Concrete Structures, T. M. Chrisp, G. Starrs, W. J. Mccarter, E. H. Owens, S. V. Nanukuttan, Niall Holmes, L. Basheer
Developments In Intelligent Monitoring Of Concrete Structures, T. M. Chrisp, G. Starrs, W. J. Mccarter, E. H. Owens, S. V. Nanukuttan, Niall Holmes, L. Basheer
Conference papers
Deterioration in concrete comprises an initiation period and a propagation period. The initiation period is characterised by changes that occur within the concrete in response to the exposure environment and continues until a stage is reached when damage begins to propagate. The propagation period begins at a point in time defined when a particular event occurs (e.g. loss of steel passivity due to chloride ingress) and continues until a specified limit state is reached. The initiation and propagation stages of a deterioration process result from a complex interaction of physical, chemical and electrochemical phenomena. Prediction of the field performance of …
The Use Of Novel Non-Destructive Methods For Quality Control And Performance Evaluation Of Concrete Structures, Sree Nanukuttan, Niall Holmes, Sudarsan Srininvasan, Lulu Basheer, Muhammed Basheer, John Mccarter, Gerry Starrs
The Use Of Novel Non-Destructive Methods For Quality Control And Performance Evaluation Of Concrete Structures, Sree Nanukuttan, Niall Holmes, Sudarsan Srininvasan, Lulu Basheer, Muhammed Basheer, John Mccarter, Gerry Starrs
Conference papers
Concrete cover provides the first line of defense against the ingress of many deleterious substances into the concrete. Therefore, a measure of its transport properties is vital in assessing its long term performance in a given exposure condition. In new structures the rate of ingress of the deleterious substances could be monitored using array of electrical sensors that are embedded in the cover concrete. For structures that are currently in service, tests can be performed by removing cores from the structure (lab based tests) or by using tests that can be performed on the surface (in situ tests). Results relating …
Developments In Monitoring Techniques For Durability Assessment Of Cover-Zone Concrete, W.J. Mccarter, T. M. Chrisp, G. Starrs, Niall Holmes, L. Basheer, M. Basheer, S. V. Nanukuttan
Developments In Monitoring Techniques For Durability Assessment Of Cover-Zone Concrete, W.J. Mccarter, T. M. Chrisp, G. Starrs, Niall Holmes, L. Basheer, M. Basheer, S. V. Nanukuttan
Conference papers
This paper outlines developments in the use of an embedded multi-electrode sensor to study the response of the cover-zone (surface 50mm) to the changing ambient environment. The sensor enables the measurement of the spatial and temporal distribution of the electrical properties of concrete and temperature within the cover-zone thereby allowing an integrated assessment of cover-zone concrete performance. Both laboratory and field results are presented to highlight the information that can be obtained from embedded sensors. When exposed to the natural environment, the temperature dependence of the electrical response is highlighted and standardization protocols are developed to account for this effect. …
A New Congested Traffic Load Model For Highway Bridges, Colin C. Caprani, Colm Carey, Bernard Enright
A New Congested Traffic Load Model For Highway Bridges, Colin C. Caprani, Colm Carey, Bernard Enright
Conference papers
Long span highway bridges are critical components of any nation’s infrastructure. Therefore accurate assessment of highway bridge loading is essential, and it is well known that congested traffic governs load effect for such bridges. Current congestion models use conservative assumptions about traffic and inter-vehicle gaps. This research investigates congested traffic flow through the use of traffic microsimulation which has the ability to reproduce complex traffic phenomena based on driver interactions. A time series model has been developed to produce a speed time-series similar to the results of the microsimulation. The speed time-series from the new model, combined with the established …
Management Strategies For Special Permit Vehicles For Bridge Loading, Bernard Enright, Eugene J. Obrien
Management Strategies For Special Permit Vehicles For Bridge Loading, Bernard Enright, Eugene J. Obrien
Conference papers
An examination of weigh-in-motion data collected recently at sites in five European countries has shown that vehicles with weights well in excess of the normal legal limits are found on a daily basis. These vehicles would be expected to have permits issued by the responsible authorities. It can be seen from the measurements that most of them are travelling at normal speeds. Photographic evidence indicates that, while many are accompanied by an escort vehicle, normal traffic is flowing alongside in other lanes. As European freight volume grows, the frequency of these special vehicles can be expected to increase. Hence, the …
Site Specific Modelling Of Traffic Loading On Highway Bridges, Bernard Enright, Eugene J. Obrien
Site Specific Modelling Of Traffic Loading On Highway Bridges, Bernard Enright, Eugene J. Obrien
Conference papers
Accurate traffic loading models based on measured weigh-in-motion (WIM) data are essential for the accurate assessment of existing bridges. Much work has been published on the Monte Carlo simulation of single lanes of heavy vehicle traffic, and this can easily be extended to model the loading on bridges with two streams of traffic in opposing directions. However, a typical highway bridge will have multiple lanes in the same direction, and various types of correlation are evident in measured traffic, such as groups of very heavy vehicles travelling together and heavy vehicles being overtaken by lighter ones. These traffic patterns affect …
The Influence Of Correlation On The Extreme Traffic Loading Of Bridges, Eugene J. Obrien, Bernard Enright, A. T. Dempsey
The Influence Of Correlation On The Extreme Traffic Loading Of Bridges, Eugene J. Obrien, Bernard Enright, A. T. Dempsey
Conference papers
Accurate traffic loading models based on measured data are essential for the accurate assessment of existing bridges. There are well-established methods for the Monte Carlo simulation of single lanes of traffic, and this can easily be extended to model the loading on bridges with two independent streams of traffic in opposing directions. However, a typical highway bridge will have multiple lanes in the same direction, and various types of correlation are evident in measured traffic. This paper analyses traffic patterns using multi-lane WIM data collected at two European sites. It describes an approach to the Monte Carlo simulation of this …