Subcategory: Civil/Mechanical/Manufacturing Engineering
Cristina Lorenzo-Velazquez - University of Puerto Rico, Mayaguez Campus
Co-Author(s): Noel Torres, University of Puerto Rico, Mayaguez Campus; Carlos Medina, NAVAIR, MD
Structures with small to intermediate damages involving cracking and separations of concrete, must be addressed with a specific repairing methodology. However, not all structures can be remedied by invasive methodology. A viable solution is to prepare a mortar capable of strengthening the original structure. It has been shown that concrete mixtures containing nanoparticles gain promising overall performance. This can be achieved because the presence of nanoparticles, in this case nanostructured SiO2, enhances some, if not most, of the concrete’s properties. For instance, it densifies its structure and favors a more efficient cement hydration. Thus, the main objective of this research has been to design a mortar for structural patchment that has sufficient bond strength with aging concrete structures to increase their tensile and compressive strength. Previous development of mortars with addition of fly ash, rendered adequate compressive results at 24 hours, 7 days, and 14 days. To improve these findings, nanoparticles have been added to partially substitute cement and to strengthen the mortar. Hence, a nano-engineered concrete is being optimized in over 20 designs of mortar mixes. These novel designs have different types of colloidal silica. Satisfactory results, in line with the products currently used to repair concrete structures, can be expected, since slump tests, penetration tests and compressive strength results seem to be adequate. After the preliminary results of compressive strength of the mix designs containing fly ash, nanosilica and superplasticizer, the samples are to be tested in larger quantities. The optimal mix designs will be selected in order to test the bond strength with fractured concrete beams and cylinders, and analyze the reaction of the designs used in each fractured beam reparation.Abstract_ERN_ Cristina_Lorenzo.docx
Funder Acknowledgement(s): This material is based upon work supported by the National Science Foundation under Grant No. HRD 1345156 (CREST Program). The materials employed in the present project were partially provided by Cemex Puerto Rico and the staff of the Construction Materials laboratory of the Department of Civil Engineering and Surveying of the University of Puerto Rico at Mayaguez.
Faculty Advisor: Oscar Marcelo Suarez, firstname.lastname@example.org
Role: As a undergraduate student in this research I have participated since the literature review before the beginning of the research, the experimental part in the development of the designs and mixtures of mortar, the tests performed and the analysis process of the data obtained.