Steel Structures

The sea vessels heading for the harbour of Amsterdam must pas the IJmuiden Locks. Due to both the navigation growth and ageing of existing structures, a new wide sea lock will be constructed there in the years to come. This paper presents the challenges of that project resulting from the narrow space conditions and close neighbourhood of two other sea locks that must remain in operation during the entire construction period. The authors represent the public waterway administration and two consulting companies involved in solving these challenges.

The protection of human life and the prevention of irreparable damages in case of fire have
become a compulsory requirement and a trend research topic. In strategic structures it is important
to limit deformations in order to guarantee the building serviceability also in case of
fire.
In this work the authors develop a procedure to estimate the deformations of a simple frame
subjected to fire. By means of the SAFIR code a nonlinear structural analysis has been considered
as a benchmark for structures under standard fire conditions. Hence, “effective temperatures”
have been determined imposing the equality of deformations obtained by linear
calculation and the ones obtained by SAFIR. The results show an acceptable error percentage
taking into account the coarse approximations involved in the procedure.
The “effective temperatures” method allows early assessments of the serviceability limit state
of complex structures partially subjected to fire.

No-fine concrete has been in use in many countries over more than a century. Its higher porosity helps in percolating rain water directly to ground and thereby helps in recharging groundwater aquifer. In this study, 3 batches of no-fine concrete each with two different sizes of aggregate were prepared to find the mix that generated high compressive strength and study the effect of percentage of fine aggregate on the compressive strength of no-fine concrete. The purpose of this project is to analyze the feasibility of producing highly sustainable no-fine concrete mixtures and evaluating the effect of fine aggregate on their properties. No-fine concrete is produced by using ordinary Portland cement, coarse aggregates, and water. This concrete is tested for its properties, such as slump value, porosity and compressive strength. The results showed that porosity has significant effect on compressive strength of no-fine concrete. The study found that of the different admixtures tested, polypropylene fibers had the largest impact in improving durability. Including polypropylene fibers in the pervious concrete mix resulted in significant increases in resistance in all three freeze-thaw durability tests. It also resulted in significant increases in abrasion resistance. By bridging the gap between the coarse aggregates, the cellulose fibers bound the pervious concrete mixture with an interwoven matrix of fibers. This also improved the compressive strength of the pervious concrete. The delayed set modifier resulted in a more fluid mix and large gains in compressive strength at seven and fourteen days and twenty eight days. This admixture may inhibit some of the cement from setting around aggregates and may result in some cement settling to the bottom and forming a less pervious layer. The viscosity modifying admixture created a more workable and easier to mold mix. Its effect on strength and durability were minimum.

Corso di formazione:
LA PROGETTAZIONE STRUTTURALE ATTRAVERSO L’ANALISI DI CASI CRITICI
Coordinatore: Prof. Ing. Franco Bontempi, Ordinario di Tecnica delle Costruzioni
Facoltà di Ingegneria Civile e Industriale della Università degli Studi di Roma La Sapienza franco.bontempi@uniroma1.it
Dettagli: Via Eudossiana 18, 00184 Roma - 7 e 8 luglio 2016, totale di 16 ore - quota iscrizione 290 euro.
Informazioni e iscrizioni: analisi-strutturale@uniroma1.it

Il presente corso vuole illustrare i concetti, i metodi e gli strumenti della progettazione strutturale e della ottimizzazione strutturale attraverso l’illustrazione di casi concreti e specifici.
La significatività dei casi presentati in questo corso, casi che ovviamente non esauriscono la enorme varietà della realtà, è rappresentata dalla loro intrinseca criticità: sono situazioni di progetto in cui si sono avuti forti condizionamenti e precisi vincoli relativamente a prestazioni da ottenere, condizioni ambientali influenti durabilità, limiti dimensionali e complessità geometrica, peso e facilità costruttiva.
In tutti questi casi, partendo dai concetti teorici, si sono utilizzati strumenti di calcolo automatico e prove sperimentali per inquadrare, affinare e definire il progetto, con interazioni fra le varie fasi che sono aspetti che il presente corso vuole puntualmente illustrare: proprio la discussione di questi dettagli specifici della progettazione (concezione – modellazione – sperimentazione – realizzazione), costituisce il fulcro del corso.