Browsing by Author "Mosquera, Luis"

Now showing 1 - 3 of 3

APPLICATION OF SELF-CURING CONCRETE METHOD USING POLYETHYLENE GLYCOL
(LACCEI Inc., 2020-07) Común, Edward; Sanabria, Arleey; Mosquera, Luis; Torre, Ana
In this investigation the method of self-curing of the concrete is applied using polyethylene glycol (PEG 400), with the aim of proposing a novel alternative of curing in the concrete that suppresses the traditional external curing of the concrete indicated in ASTM C31, in order to obtain expected compression resistance results, observing the development of concrete hydration processes. The experimental campaign included the production of 159 cylindrical specimens of dimensions 10x20 cm and 18 beams of dimensions 15x15x50 cm. Relationships a / c = 0.70, 0.60 and 0.45 and resistance tests at ages 7, 14 and 28 days were considered. Dosages of PEG 400 were used in 0.5%, 1% and 1.5% of the cement weight for the determination of the dosage that provides the best compression resistance results. Concrete properties were characterized such as tensile strength by diametral compression, rupture modulus, and its microscopic composition was observed using SEM scanning microscopy. Finally, it was obtained that for the age of 28 days of concrete, the dosage of 1% of the cement weight for the additive PEG 400 provides the most satisfactory results of compressive strength, diametral compression traction and rupture modulus, both for a / c = 0.70, 0.60 and 0.45.
Measurement of the speed of absorption of CO2 by Portland cement pastes and pure and additive mortars
(LACCEI Inc., 2020-07) Mosquera, Luis; Valerio, Joe; Basurto, Jesús; Quintana, Noemi; Torre, Ana
We present here the results of experimental research on the speed of absorption of CO2 by Portland cement pastes and pure and additive mortars. The samples, introduced in a chamber, are exposed to a high concentration of CO2, simultaneously monitoring the temperature, relative humidity, pressure and concentration of CO2 present inside. The results show greater rapidity of carbonation both in cement pastes and in mortars when they are added with plasticizers, air incorporators or workability additives.
Monitoring of stresses and deformations in soils by fiber optic sensors
(LACCEI Inc., 2018-09) Mosquera, Luis; Basurto, Jesús
This paper shows the application of LPG optical fiber sensors to the determination of the transmitted stress and deformation of a sample of confined soil subjected to surface loads. The transmitted stress was measured by a mechanical LPG pressure sensor and the curvature of the ground by permanent LPG sensors buried at depths of 0.1m; 0.2m; 0.4m and 0.6m. Clay-sandy soil characteristic of UNICAMP was deposited in a cylinder of 0.8m in length and 0.30m in diameter. The soil was lightly compacted in 0.2m layers and an LPG sensor was installed on each layer. Surface loads of up to 227 KPa were applied to the surface of the soil, measuring axial soil deformations of less than 3mm by our sensors with sensitivities of the order of 0.22 mm/dB. The values of the modulus of elasticity for this type of soil were determined from the fitting of the Boussinesq equations with the values measured by the buried LPG sensors. A Young's modulus of 5.40 MPa and a Poisson's coefficient ν = 0.52 were determined for this type of soil.