Search results for "Concrete."
showing 10 items of 249 documents
The role of nanoparticles in decreased washout of underwater concrete
2019
Abstract The paper presents research results of the influence of SiO2 nanoparticles on the washout of underwater concrete and hardened concrete. Based on infrared spectroscopy (FTIR) and thermogravimetric (TGA) analyses of the applied anti-washout admixture (AWA), its chemical structure was determined. A beneficial effect of SiO2 nanoparticles on the reduction of the mix washout was demonstrated and the most probable reason for that phenomenon was given, taking into account the AWA chemical structure and its behaviour in the concrete mix environment. It was found that a dosing method of AWA and nanoparticles to the concrete influenced the washout.
Experimental Investigation of the Shear Response of Precast Steel-Concrete Trussed Beams
2017
The results of an experimental campaign of three-point bending tests on precast composite beams, named hybrid steel-trussed concrete beams (HSTCBs), are provided. HSTCBs are typically constituted by a precast steel truss embedded in a block of concrete cast in place. Two series of specimens were manufactured, designed such that shear failure would occur, and tested under positive and negative bending moment. The experimental results obtained showed that fragile shear failure occurred in almost all cases, evidencing the crisis of the compressed concrete strut involved in the collapse mechanism. Yielding of the steel members provided ductility to the system, especially in those cases in which…
A material for memory
2022
Every piece of architecture always aspires to become a monument, if only for the intentionality of meaning, witness and duration that becomes suggestive and evident through the etymological interpretation of the Latin verbs memini, moneo, maneo: every construction, in fact, it recalls the sense of its necessity and essence; it admonishes by arousing respect with the force of the image and the meaning it conveys; it remains durable and, ideally, eternal. There are, then, the architectures specially built to remember in which the utilitas transcends the usual considerations of functional type and sublimates itself in the manifestation of the memory, while the fi rmitas conserves and maintains…
Steel fibre and transverse reinforcement effects on the behaviour of high strength concrete beams
2012
An experimental program was carried out to investigate the influence of fibre reinforcement on the mechanical behaviour of high strength reinforced concrete beams. Eighteen beams, loaded in fourpoint bending tests, were examined by applying monotonically increasing controlled displacements and recording the response in terms of load-deflection curves up to failure. The major test variables were the volume fraction of steel fibres and the transverse steel amount for two different values of shear span. The contribution of the stirrups to the shear strength was derived from the deformations of their vertical legs, measured by means of strain gauges. The structural response of the tested beams …
Flexural Response of Reinforced Concrete Beam on Elastic Foundation under Vertical Load and Bending Moment: Review of Existing Methods and Proposed N…
2021
AbstractThis work examined the behavior of a RC beam on a soil foundation subject to concentrated vertical loads and bending moment in both the elastic and the plastic phases. Some of the simplifie...
Strength and Ductility of Hollow Circular Steel Columns Filled with Fibre Reinforced Concrete
1999
Publisher Summary This chapter investigates the behavior of hollow circular steel cross-sections filled with Fiber Reinforced Concrete (FRC), subjected to monotonic loads. The casting of different types of composite members—steel columns, steel columns filled with Normal Strength Concrete (NSC), and steel columns filled with Fiber Reinforced Concrete (FRC) was employed. The columns were tested in uniaxial compression utilizing a universal testing machine operating in displacement control. The maximum strength of composite members filled with FRC was 20% higher than that recorded for steel pipes filled with FRC. After the peak load was reached, failure was due to the crushing of concrete and…
BuscaPalabras: a program for deriving orthographic and phonological neighborhood statistics and other psycholinguistic indices in Spanish.
2005
This article describes a Windows program that enables users to obtain a broad range of statistics concerning the properties of word and nonword stimuli in Spanish, including word frequency, syllable frequency, bigram and biphone frequency, orthographic similarity, orthographic and phonological structure, concreteness, familiarity, imageability, valence, arousal, and age-of-acquisition measures. It is designed for use by researchers in psycholinguistics, particularly those concerned with recognition of isolated words. The program computes measures of orthographic similarity online, with respect to either a default vocabulary of 31,491 Spanish words or a vocabulary specified by the user. In a…
Iconicity and Typography in Steve McCaffery's Panel-Poems
2007
This paper discusses Steve McCaffery's "Panel-Poems", first realized in the 1960s, with respect to the international context of concrete poetry and the emergence of a poetics of iconicity amongst a North-American avant-garde in the second half of the twentieth century. The material emphasis of McCaffery's poetry is played out typographically in his work "Carnival" (1967-75) through procedures that place the letter, the smallest denominator of language and the page in newly imagined networks of signification. The experiment with the environment of writing is sustained by a reliance upon the typewriter and other forms of scription that conceive of the reader as an active participant in the cr…
STRUCTURE, ENVELOPE AND TECHNOLOGICAL INNOVATION The reinforced concrete in the construction of very tall buildings
2014
Until the second half of the nineteenth century, ie until the Industrial Revolution, the building structures played static function and also protective function. In the course of time separating the combination goes. The introduction of iron leads to a progressive "innovation" of building structures. The first application of iron in construction dates back to the mid-nineteenth century. They were first made with cast-iron columns and beams in iron and later with particular types of steel. The architecture of the iron is a true regeneration of the way of building, the cities are filled with sophisticated solid structures and slim at the same time, it enhances the transparency of glass, it in…
A reckoning with the maintenance of the built environment, a Sisyphean task
2023
Maintenance concerns most of the artifacts, referring simultaneously to the socio-cultural, technical and managerial spheres. Contemporary scenarios impose an overall rethinking, where key-topics such as tradition, consumerism, sustainability and digitization become pivotal in the search for suitable production models, between post-industrial and neo-craftsmanship, in order to have fresher references for the maintenance activities.
 In the construction field, maintenance is not limited to the objective of prolonging the duration of quality levels that only affect direct users, but also has important implications of a social and collective nature, in the case of both public and private …