The present research work shows the effect on the carbonation of Portland cement-based mortars (PC) with the addition of green materials, specifically residues from two groups: agricultural and industrial wastes, and minerals and fibres. These materials have the purpose of helping with the waste disposal, recycling, and improving the durability of concrete structures. The specimens used for the research were elaborated with CPC 30R RS, according to the Mexican standard NMX-C-414, which is equivalent to the international ASTM C150. The aggregates were taken from the rivers Lerma and Huajumbaro, in the State of Michoacan, Mexico, and the water/cement relation was 1:1 in weight. The carbonation analyses were performed with cylinder specimens in an accelerated carbonation test chamber with conditions of 65 +/− 5% of humidity and 25 +/− 2 °C temperature. The results showed that depending on the PC substitutions, the carbonation front advance of the specimens can increase or decrease. It is highlighted that the charcoal ashes, blast-furnace slags, and natural perlite helped to reduce the carbonation advance compared to the control samples, consequently, they contributed to the durability of concrete structures. Conversely, the sugarcane bagasse ash, brick manufacturing ash, bottom ash, coal, expanded perlite, metakaolin, and opuntia ficus-indica dehydrated fibres additions increased the velocity of carbonation front, helping with the sequestration of greenhouse gases, such as CO2, and reducing environmental pollution.
Adobe masonry is one of the oldest construction systems still in use today, Mexico has an enormous cultural heritage with traditional adobe houses being very representative of the rural communities and their culture. The 2017 Puebla Earthquake on September 19th struck the country causing the loss, destruction, and damage of historic buildings in several Mexican states, with the traditional earthen dwellings being the most vulnerable structures to these events. The fast abandonment of the local materials and techniques entails further research regarding the characterization of these construction systems, therefore, reconstruction efforts first require the recovery of the construction technique. After the seismic events, adobe samples of the remaining adobe structures of Jojutla de Juarez were collected. This population was one of the most affected in all the country, and, because of the major losses suffered, the study was conducted to determine the material properties of the dwellings’ adobe shards and natural quarry clays of the region. The characterization included destructive and non-destructive tests, mineralogical and granulometry analyses, and composition of the adobe samples of the buildings, as well as the aggregates. As a novelty, the compressive strength of the pieces was tested by two methods: the traditional compression strength test and the point-load test, in order to obtain the indicative values and the correlation equations between both tests. From the formal analysis and the laboratory, it was observed that the adobes from Jojutla presented different compositions which combined with the building malpractices and alterations to the traditional systems caused unpredictable behavior during the earthquake. The conduction of point-load tests in situ, as a part of a complete characterization methodology, could be an alternative to study the mechanical properties of patrimonial or damaged building samples before its disappearance.
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 the natural environment. The present research work consisted in the design and development of asphalt mixes with a partial substitution of the natural aggregate (NA) by means of recycled concrete aggregate (RCA). The mix was designed with the Marshall methodology, considering the next percentages of substitution and addition by mass: 90% NA and 10% RCA; 80% NA and 20% RCA; 70% NA and 30% RCA. The mixtures were elaborated and analysed under the international standards and the Mexican regulation of the Communications and Transport Ministry, to determine the best option regarding their performance. The materials were characterized according to the current regulations and later employed in the mixes design. A total of 38 specimens were elaborated for each mixture, determining the optimum asphalt content; after that, mechanical tests were performed to analyse and determine the best results. In the aftermath of the examination of all mixtures, we concluded that the 70%AN/30%RCA is the best alternative option according to its performance and numeric results, complying with the cited regulations, and allowing a lower content of asphalt during the process.
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.
Research work was carried out on rocks obtained in the municipality of Tlalpujahua Michoacán, located in different quarries of stone material, classifying the name of the quarry with the name of the community where the stones are located: “El moral” stones of bronze (BR) and golden (D) color, “la américa” stones of gray (G) and pink (R) color, “llano grande” stones of dark brown (CO), reddish-brown (CR) and black (N) color. Physical and mechanical tests were carried out, evaluating the percentage of moisture absorption, density, and absolute density. To evaluate the mechanical properties, the following tests were performed: uniaxial compressive strength (UCS), and static flexural test (modulus of rupture). The comparison of the different physical-mechanical tests allows estimating their behavior as a structural and restoration element. The correlation obtained to estimate the UCS has an acceptable correlation coefficient.
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