Foamed bitumen improves the properties of base layer, increasing the number of equivalent axles allowed, as result of this is a durable pavement. To achieve this, base layer’s design must count with an amount of filler, to increase the stony aggregate fraction. This research consists with two different types of filler, lime and cement, 1% in dosage respect to the stony aggregate weight. Has been discovered now, that the RAP (reclaimed asphalt pavement) aggregate in addition to mitigate environmental problems, has a significant impact value on the mechanic resistance of the mix.
Damage to the rocks of historic built heritage needs to be addressed to facilitate their conservation and restoration; the most serious damage is caused by environmental conditions and human activities. Buildings constructed with ignimbrite blocks bonded with lime mortar in Morelia, México, a UNESCO World Heritage site, were studied. The damage mainly occurs in the facades, on the surfaces of the rocks and in the mortar of the union exposed to climatic factors such as sun, rain, wind, and temperature changes, due to the actions of humans and vehicles emitting polluting gases; and due to pigeon excrement. This has caused the formation of patinas and flora, reduced the mechanical strength and exfoliation, decreased the density and cohesion in the mortar with rocks, and led to friction damage caused by people. In the facades of five buildings, the mechanical resistance and microstructural characteristics were indirectly determined by XRD, XRF, and SEM. The results were related to the climate, humans, and vehicular pollutant emissions. The damage was due to the environment, the influencing geographic orientation, and prevailing winds, rising capillary water on the facades, pigeon droppings, vehicular pollutant gases, and humans. Potential banks of healthy quarries were analyzed for use in the conservation and restoration of damaged monuments.
Materials play a fundamental role in any branch of civil engineering. From ancient times to the present day, society has required enormous amounts of construction materials, which implies an excessive exploitation of materials that come directly from nature. This paper explains the main differences, similarities, benefits and characteristics of the 2 designs of asphalt mixtures by means Marshall methodology. The first design is for control mixture, which was elaborated with a conventional asphalt AC-20 and 100% of natural aggregate (NA). The second design is for asphalt mixture with 30% of recycled concrete aggregate (RCA) and 70% of NA. Finally, it was determined that both designs have similar characteristics, which indicates that the use of 30% RCA in asphalt mixtures is adequate. In addition, it represents economic and environmental savings.
The creation of sustainable hydraulic concrete from the use of waste materials, such as PET bottles, whose performance is better than the conventional concrete, has been a great challenge worldwide within the construction industry. This article shows a study on the application of PET fibers resulting from the recycling of post-consumer bottles, which will help increase their physical and mechanical behavior. Two concrete mixtures were made: a control mixture (M-C), with the proportions of a conventional concrete and a second mixture, adding 0.8% of PET fibers with respect to the cement mass (PR-0.8). Tests of electrical resistivity, ultrasonic pulse velocity, compressive strength, tensile strength and flexural strength were performed at the ages of 7 and 28 days. The results showed a slight improvement in the mechanical behavior of the PR-0.8 mixture, in contrast to the M-C mixture, given that a non-sudden failure occurs; while that the tests of electrical resistivity and pulse velocity indicate that the concrete produced is of good quality and durable.
This research is an investigation about the use of powder material additions with mortars lime base for a possible implementation in construction and/or restoration of historical sites. Mortars were elaborated in laboratory conditions with a 1:2.5 in weight proportion. One of the proofs to which these mortars were submitted was the test of capillary absorption; this way, the influence of the materials added to powder in these mortars determined porosity. Mortars were made with different percentages of materials. These powder materials are brick manufacturing ash, quarry powder, clay and maize starch. The test was run during 350 to 700 days. It obtained better results with 700 days than with 350 days.
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