Artigos científicos, teses e dissertações
Publicados nas melhores instituições de ensino

This work presents an experimental study of the behavior of transverse joints in unreinforced concrete slabs under elastic support. Due to the tensions caused by loads and volumetric variations in the slab, transverse joints when badly executed can cause a efficiency reduction in...

This study presents the effects of recycled concrete aggregate (RCA) on the key fresh and hardened properties of concrete. RCA was used to produce high-workability concrete substituting 0-100% natural coarse aggregate (NCA) by weight. The slump and slump flow of fresh concretes w...

This paper reports the strength behaviour of concrete containing three types of recycled polyethylene terephthalate (PET) aggregate. Results are also analysed to determine the PET-aggregate's effect on the relationship between the flexural and splitting tensile strengths and comp...

Along the past forty years, an increasing interest on composite materials formed by the addition of discrete fibers to a concrete matrix is being observed. These composites are known as fiber reinforced concretes. The interest on the use of fibers as reinforcement is justified by...

The compressive strength of concrete is one of the most important features for design and to assure good quality of structures. Compression tests allow a direct evaluation of the compressive strength of concrete, either in precast test specimens or in samples extracted from an ex...

In inspections of buildings, it is increasingly common to come across buildings and infrastructure works, long before they reach their useful life, are already in need of repair and reinforcement, or collapsing. This study examined the bond between concrete of different ages and ...

Abstract Concrete barriers prevent vehicles from entering the opposite lane and going off the road. An important factor in the design of concrete barriers is impact load, which a vehicle exerts upon collision with a concrete barrier. This study suggests that a height of 813 mm, a...

This work investigates the strength of a concrete anchor system constituted of headed studs embedded in concrete subjected to impact tension load. The main variable was the loading rate which varied from a minimum of 0,015 kN/s (static) to a maximum of 54885 kN/s. The anchor syst...

The low relation strength-weight of concrete, when compared to steel, constitutes a disadvantage of that material when applied in the construction. To improve this relation we can reduce the specific gravity of the concrete or increase its strength. Nowadays,lightweight concrete ...

The Brazilian standard NBR 7212 (ABNT, 1984), for execution of ready-mixed concrete, specifies the maximum time for concrete to be discharged (used) completely in 150 minutes. The usage time of the concrete is due to reactions of the cement hydration and slump loss that occurs wi...

ABSTRACT Self-Compacting Concrete (SCC) flows around obstructions by its self-weight to fill entirely and self-consolidate (without any need for vibration), without any part of disconnection and chunking. The eradication of the need for consolidation leads to better quality concr...

Abstract There are some ways to extend the service life of a reinforced concrete structure. This paper focuses on the extension of the service life by treating the surface of reinforced concrete, specifically on the effect of the concrete cover thickness on the surface treatment ...

Concrete is the most used material in the construction industry worldwide. Built concrete infrastructure is exposed to specific environments conditions during the asset’s life, which impose chemical and physical actions that may lead to premature deterioration. Poor concrete dura...

The use of lightweight concrete is mainly due to the benefits provided by reducing the density of the material such as smaller efforts on structures, economy of molds and scaffolding, as well as lower costs of transportation and erection of precast constructions. Currently, besid...

ABSTRACT Nanotechnology can significantly improve the mechanical strength and durability of concrete. At the nanoscale, good dispersion of constituent materials is an essential factor for the improvement of concrete properties. In this scenario, the objective of this research was...

Concrete structures must be designed and constructed so as to resist the conditions established in the project design and suffer no deterioration for many years. In highly aggressive environments, in addition to the minimum layer covering the framework, the concrete must receive ...

The use of concrete filled steel tubes especially in tall buildings is a tendency in several european, american and asian countries. The use of these members has several advantages: high resistance and ductility, saving of materials and labour, reduction of cross section dimensio...

Slurries containing Portland cement concrete are generated from concrete mixer trucks and other concrete-coated equipment in concrete washout area. This work presents some of the results of an investigation on the possible applications of aggregates from recycled concrete mixer t...

This paper presents analytical and experimental results on ductility of reinforced lightweight concrete beams and columns in the form of moment curvature relationships, and compares the response with that of normal reinforced concrete members. The experimental part is limited to ...

ABSTRACT The addition of fibers to the cementitious matrix, giving rise to fiber-reinforced concrete, aims to improve the low ductility observed in concrete mechanical response under different load scenarios, particularly under direct tension. In this work, cracking and mechanica...

This research had as an objective the proposition of a group of measures that can be used to improve labor productivity in buildings structures concrete placement. At first this work raised data on the subject of labor productivity in concrete placement and on the method of obtai...