The results of an experimental study of two confined masonry walls and two reinforced masonry walls with reduced quantity of reinforcement are presented.

The full scale walls were made of hollow concrete blocks and were tested with horizontal cyclic loads. The dimensions of the walls were 3650x2250 mm

and the thickness of the walls was 140 mm. The cross-sectional area of horizontal reinforcement is 0.0003 times the gross-sectional area of the reinforced

masonry wall. The cracking and damage patterns, strength and stiffness degradation and deterioration, energy dissipation capacity and displacement capacity

after the cracking are analyzed. The conclusions are useful for the seismic design of one and two stories masonry dwellings.

The objective of this research was to apply and validate the Nested Anova Model as an analysis tool of the uniformity of ready-mixed concrete production.

In theory this method allows the decomposition of the total variance (

total

total

2

batch-to-batch

+

within-batch

+

within-test)

, being the batch the basic unit of production. This variance decomposition allowed assessing the contribution of

each component to the total variance of the studied property, in the same unit of measurement and in relative terms.

The method was successfully applied to an actual ready-mixed concrete production and distribution study case. It was concluded that the main source of

concrete strength variability was the within-batch variation (51.5%; normal delivery condition without the addition of water on site). The batch-to-batch

variability resulted to be the second most important contributor to the strength variation (41.1%). The variability attributable to the control laboratory (or

within-test deviation estimated based on differences in strengths of companion test cubes made from the same sample of concrete) resulted to be the smallest

contributor to the strength variation (7.4%). The results clearly show that the main cause of concrete strength variability was a deficient homogenization of

the concrete during the mixing process in the mixer trucks, and therefore there is a great opportunity for improvement of the company.

2

2

=

2

) of the concrete strength, or any other property to be evaluated, as the sum ofits components. In the present study the following components were considered: “batch-to-batch”, “within-batch” and “within-test or laboratory” (

2

Chile is undergoing a transition process towards economic development through the last decade. Just as it has happened previously in other countries, this

development can have a serious impact on the environment. In both senses the Construction Industry plays a very important role. In this context, the paper

presents the results of a research where was used fly ash for lightweight aggregates production to structural concretes. The result of these research allowed

to comprobe the technical viability to fabricate these products. The degree of Sustainability of the material development was evaluated with a methodology

what alloved to generate a stamp of certification or “green seal” to certify construction materials, aspect also detail it in this paper. Like a conclusion, this

paper presents two ways to advance toward the sustainability, establishing lineaments to point at a sustainable construction by means of the application of

clean technologies. In this sense it obtain develop an artificial aggregates with adequate physical and mechanics properties to use in structural lightweight

concretes, on the other hand, was development a tool to the certify the environmental performance, evaluating the associates impacts during the life cycle

of the construction materials.

At present time and for several years, some different concretes have been developed for special purpase. The most used procedure is to modify the cement

based matrix, to improve some properties, subtitrating components or using admixtures, additions or both. Among these special concretes is the concrete

with fibers, that according to ACI 544-3R-84: " fiber reinforced concrete is a composite material made of hydraulic cements, fine and gross aggregate, and

a dispersion of discontinuos, small fibres". This paper analyzes the influence of the type and percentage of glass fiber, on the concrete physical mecanic

properties. For this differents mixes were made changing the type and percentage of glass fiber added. The results are compared with those of a standard

mix. The physical mechanical properties as workability, plastic cracking, toughness, abrasion and impact resistance.

This work presents an innovative method to determine the degree of bridge corrosion deterioration of the Federal Highway Network in Mexico, as a function

of environmental factors such as prevailing climate where the bridge is located, bridge geographic positioning (e.g. coastal line, river or lake distance) and

the distance from an industrial corridor. The information was obtained and analyzed using last generation Global Positioning Systems (GPS). This work

also presents the preliminary results of the corrosion damaged-induced Mexican Federal bridge inventory.

The Mining of copper generates great amounts of debris which come from the process of leaching by Sulfuric acid, which are discarded and then accumulated.

In the process of finding alternative methods, the present research pretends to find the positive and negative effects of using this type of concrete, given

the fact that these accumulate an appreciable amount of copper sulphate and some other impurities, which tend to reject their utilization. Because of the

great amount of fines, sulphates and chlorides it was necessary to wash out the material before it was used. Concretes were made, each an every one had

a different water/concrete (w/c) relationship, maintaining the consistency and the relationship burdens-sand constant, also varying the type of cement and

comparing results with a pattern concrete elaborated with barren normal thickness. The results show us that the washing out of the materials only has a

great efficiency in the elimination of fines, but not in the elimination of chlorides and sulphates. The test concretes made of leaching debris had a slightly

greater resistance the first days and show a tendency that would indicate a lost one of resistance with the age. The survey concluded that this material can

be used for secondary concrete structures, which would be useful for a short time in dry surroundings.