Population grow in recent years requires an extension of the current pipeline sanitary system. For this purpose, granular excavation and landfill works are associated with pedestrian traffic congestion. Therefore, it is necessary to develop an innovative and sustainable alternative to reduce the problems generated during the execution of the conventional process. This research proposes the use of flowable fill due to the multiple advantages offered by this material. On the one hand, it is economical for medium to large trench fill volumes, considering savings in labor (it is done with a small number of workers), in equipment (does not require the rental or purchase of compaction equipment) and in time (the pouring is done by directly pumping the mixture, from the mixing machines to the excavation). On the other hand, being self-compacting and self-leveling decreases the width of the trenches, reducing excavation and filling volumes; which, in turn, incur money savings. Also, this material guarantees work safety, since people are not required inside the excavation and fill in poorly accessible areas without any problem. Dosages were established for ten flowable fill mixtures with cement contents of 50, 60, 70, 80 and 90 kg of cement and a range of admixture from 1.75 to 2.00%; The results indicated that decreasing the fine aggregate - coarse aggregate ratio, the compressive strength of the mixtures increases and the slumps of the mixtures decreases, and the compressive strength increases directly proportional to the cement content.

Controlled Low Strength Materials (CLSM) are cementitious self-compacting materials, comprised of low cement content, supplementary cementing materials, fine aggregates, and water. CLSM is typically used as an alternative to conventional compacted granular backfill in applications, such as pavement bases, erosion control, bridge abutments, retaining walls, bedding and backfilling of pipelines. This dissertation presents the findings of an extensive study carried out to determine the corrosivity of CLSM on ductile iron and galvanized steel pipelines. The study was performed in two phases and evaluated more than 40 different CLSM mixture proportions for their corrosivity. An extensive literature survey was performed on corrosion of metals in soils and corrosion of reinforcement in concrete environments to determine possible influential factors. These factors were used as explanatory variables with multiple levels to identify the statistically significant factors. Empirical models were developed for percent mass loss of metals embedded in CLSM and exposed to different environments. The first and only service life models for ductile iron and galvanized steel pipes embedded in CLSM mixtures were developed. Models indicated that properly designed CLSM mixtures can provide an equal or longer service life for completely embedded ductile iron pipes. However, the service life of galvanized pipes embedded in CLSM should not be expected to be more than the service life provided by corrosive soils.

Flowable fill was used to strengthen the soft soil surrounding piles and behind the pile cap. The flowable fill placed beneath the pile cap surrounding the piles showed no appreciable increase in lateral resistance, this was partially due to the fact that the flowable fill placed had an unconfined compressive strength of 30 psi. Flowable fill was also used to replace a 12 ft wide, 6 ft thick, and 6 ft deep zone consisting of an average 475 psf clay that was adjacent to a 9-pile group in 3x3 pile configuration capped with a 9 ft x 9 ft x 2.5 ft, 5000 psi concrete cap. The flowable fill placed behind the pile cap had an unconfined compressive strength of about 137 psi. Lateral load testing of the pile foundation was then undertaken. The results of this testing were compared with similar testing performed on the same foundation with native soil conditions. The lateral resistance of the native soil was 282 kips at 1.5 inches of displacement, and the total lateral resistance of the pile foundation with flowable fill placed behind the pile cap was increased by about 53% or 150 kips. Of the 150 kips, 90% to 100% can be attributed to the increased passive force on the face of the flowable fill zone and shearing of the base and sides denoting that the flowable fill zone behaved as a rigid block. The long term strength of the flowable fill when water is allowed to flow over it is still in question. Samples of the 137 psi flowable fill were cured in a fog room for 700 days and showed a 56% decrease in their unconfined compressive strength. Any increase in lateral strength from the flowable fill would be compromised over a period of time less than 700 days. Site specific characteristics concerning water flow would need to be evaluated to determine if flowable fill would be an acceptable material to increase the lateral resistance of a pile group.

El Relleno Fluido o también conocido como Material Controlado de Baja Resistencia (CLSM por sus siglas en inglés) vienen siendo requeridos sobre todo en épocas de pandemia por el COVID-19 en lugar del relleno compactado, debido a su gran facilidad y rapidez para los rellenos de cavidades de zanjas, tanto en redes de agua, desagüe y alcantarillado, relleno de cimentaciones de edificios y puentes, entre las principales aplicaciones. El presente estudio contempla el desarrollo de mezclas con contenidos de cemento Portland tipo I de 60 a 90 kg/m3 para rangos de resistencia a compresión entre 5 a 15 kg/cm2 a 28 días, con agregados de la cantera Tinguiña de Ica, y aditivo agente espumante para conferir la fluidez y trabajabilidad necesaria que facilite su colocación en obra. Resultados satisfactorios de fluidez entre 9 ½” a 10 ½” y pérdida de fluidez promedio de 2”/ hora, y rangos de resistencia de hasta 24 kg/cm2 fueron obtenidos, los cuales permitieron un buen comportamiento costo beneficio tanto en ahorro económico, y tiempo de ejecución propuesto para un proyecto real de saneamiento en la ciudad de Ica. Asimismo, gracias a la aplicación de las mezclas de Relleno Fluido propuestas, se preservará el distanciamiento social durante su empleo en obra, dado que solo requiere de una persona para su aplicación en los rellenos de zanjas. / Flowable Fill or also known as Controlled Low Resistance Material (CLSM) have been required especially in times of pandemic by COVID-19 instead of traditional compacted fill, due to its great ease and speed for fillings works of trench cavities, both in water and wastewater networks, filling for foundations in buildings and bridges, among the main applications. The present study contemplates the development of mixtures with Portland cement type I from 60 to 90 kg / m3 for 28 days compressive strength ranges between 5 to 15 kg / cm2, coarse and fine aggregates from the Tinguiña quarry, in Ica city, and foaming agent chemical admixture to provide the adequate fluidity and workability to cast in place at the job site. Satisfactory fluidity results between 9 ½ ” to 10 ½” and average fluidity loss ratio of 2 ”/ hour, and compressive strength ranges of until 24 kg/cm2 were obtained, which a good cost-benefit performance both in economic savings, and execution time for a proposed sanitation project in the city of Ica. Likewise, thanks to the application of the proposed flowable fill mixtures, social distancing will be preserved during its use on site, because it only requires one person to apply it in the trench fillings. / Tesis