Professor Kruno Tonkovic (Fig. 1) was one of the greatest Croatian bridge builder of all times. In his lifetime he built many important bridges and other structures. He wrote several structural ...engineering books and scientific papers. He also educated many generations of Croatian builders, and in his specific way he initiated and envisioned numerous projects for the future. Some of them were completed a few years or even a decade after he designed them and some still wait to be completed.
Two Notable Arch Bridges on The Croatian Adriatic Highway Radic, Jure; Savor, Zlatko; Mandic, Ana
Structural engineering international : journal of the International Association for Bridge and Structural Engineering (IABSE),
02/2010, Letnik:
20, Številka:
1
Journal Article
Recenzirano
The construction of the Adriatic highway is one of the greatest financial and building projects that have ever been undertaken in Croatia. In this paper, two notable arch bridges on this highway are ...described in detail. The building of the new concrete arch Maslenica Bridge marked the beginning of construction of the new highway. The arch is of 200 m span with a rise of 65 m and was constructed by free cantilevering. The superstructure consists of eight simple-span precast prestressed girders made continuous and interconnected by concrete deck slab cast in situ. The bridge design was strongly influenced by the severity of the maritime environment and the high winds on the site. The Krka Bridge crosses the Krka River canyon in the proximity of the entrance to the environmentally very valuable and protected area of the National Park. The arch type structure was the logical choice for the canyon crossing. The reinforced concrete arch has 204 m span and 52 m rise. A slender composite steel-concrete superstructure was selected to blend more harmonically with the beautiful environment and to reduce weight and thus seismic forces at the highly seismic bridge site.
All civil engineering structures are deteriorating in time, at a different rate. The current and future states of a structure are associated with various degrees of uncertainty, and, therefore, a ...probabilistic approach is appropriate in order to predict future needs for maintenance and repair. Some existing models use discrete-time Markov processes called Markov chains. In this paper, homogeneous Markov processes (HMPs) with a finite set of condition states and a continuous parameter (time) are used. The aim is to make a probabilistic forecast of the condition of the structure, using time as a continuous parameter, so that probabilities of condition states can be calculated at each moment. The model is applied to the calculation of probability of possible future deterioration of the piers of Krk bridge (Croatia) that have already been repaired.
The paper deals with accurate determination of the relationship between bending moment and curvature of hollow rectangular bridge columns. With the calculation procedure to determine accurate curve ...of relationship, the method of determining the idealized diagram typically used in practice is also shown. The aim of this work is to point to a reserve in load capacity of an element when comparing the results of an accurate curve and the idealized diagram, and to analyse the impact of various calculation situations on the curve shape. The conclusion is that for practical use it is sufficient to use the idealized diagram, but for detailed scientific analysis the exact relationship between bending moment and curvature must be determined.
Predmet rada je točno određivanje odnosa momenta savijanja i zakrivljenosti šupljih pravokutnih stupova mostova. Uz postupak proračuna točne krivulje odnosa prikazan je i način određivanja ...idealiziranog dijagrama obično korištenog u praksi. Cilj rada je ukazati na zalihu nosivosti elementa u usporedbi točne krivulje i idealiziranog dijagrama te analizirati utjecaj različitih proračunskih situacija na oblik krivulje. Zaključak je da je za praktičnu uporabu dovoljno koristiti idealizirani dijagram dok se za detaljne znanstvene analize mora određivati točan odnos momenta savijanja i zakrivljenosti.
► During the production of cement it is necessary to add a reducing agent to convert Cr VI into Cr III. ► This paper explores effects of iron(II) sulphate on corrosion of steel reinforcement. ► ...Accelerated corrosion testing in pore solutions was performed. ► Results indicate that iron(II) sulphate may foster or accelerate steel corrosion. ► Further research is needed on steel corrosion in concrete environments.
During the production of cement it is necessary to add a reducing agent that converts soluble hexavalent chromium into trivalent chromium. This paper explores effects of iron(II) sulphate reducing agents, namely monosulphate and heptahydrate, as cement admixtures, on corrosion of concrete reinforcement. Accelerated corrosion tests of reinforcing steel have been performed in pore solutions simulating concrete prepared using either CEM I or CEM II type cement, with addition of various concentrations of iron(II) sulphate reducing agent. All of the test results indicate corresponding tendencies and point towards the potential for iron(II) sulphate to foster or accelerate corrosion of the reinforcement. The results of this study indicate an immediate need for a more detailed research, especially in concrete as a more realistic corrosion environment, of the application of iron(II) sulphate as a reducing agent in cement.
Given that visual inspection is vital when evaluating the condition of bridges, it plays a crucial role in planning the special maintenance works. At the beginning of 2012, a research was conducted ...in HAC (Croatian Highways) aiming to standardize evaluation of bridges. The bridge engineers had assessed a certain group of buildings, and their results were afterwards analysed using the mathematical statistics methods. The obtained results showed weaknesses in the existing evaluation system, and the conducted research created a base for improving aides for management, handbooks and procedures for bridge inspection.
The bridge management system used on the national road network of the Republic of Croatia does not contain the deterioration forecasting model that could be used for planning future remedial ...activities. A database on the condition of bridge elements has nevertheless been compiled, containing numerical values of the degree of deterioration. Results obtained by analysing usability of three deterioration models are presented in the paper in order to estimate which one would be the most favourable for Croatian conditions. The model based on the Markov process was found to be the most appropriate.Original Abstract: The bridge management system used on the national road network of the Republic of Croatia does not contain the deterioration forecasting model that could be used for planning future remedial activities. A database on the condition of bridge elements has nevertheless been compiled, containing numerical values of the degree of deterioration. Results obtained by analysing usability of three deterioration models are presented in the paper in order to estimate which one would be the most favourable for Croatian conditions. The model based on the Markov process was found to be the most appropriate.
Vizualni pregled je glavno pomagalo za ocjenjivanje stanja mostova, stoga ima presudan utjecaj na planiranje radova izvanrednog održavanja. U Hrvatskim cestama je početkom 2012. godine provedeno ...istraživanje s ciljem postizanja ujednačenosti pri ocjenjivanju mostova. Inženjeri za mostove ocijenili su određeni skup građevina, a potom su rezultati analizirani metodama matematičke statistike. Dobiveni rezultati upućuju na slabosti postojećeg sustava ocjenjivanja, a s provedenim istraživanjem stvorena je podloga za unaprjeđenje pomagala za gospodarenje, priručnika i postupaka za preglede mostova.
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