Expansive soils are a worldwide problem that poses several challenges for civil engineers. Such soils swell when given an access to water and shrink when they dry out. The most common and economical method for stabilizing these soils is using admixtures that prevent volume changes. In this study the effect of using rock powder and aggregate waste with lime in reducing the swelling potential is examined. The expansive soil used in this study is prepared in the laboratory by mixturing kaolinite and bentonite. Lime was added to the soil at 0 to 9 percent by weight. Aggregate waste and rock powder were added to the soil at 0 to 25 percent by weight. Grain size distribution, Atterberg limits and swell percent and rate of swell of the mixtures were determined. Specimens were cured for 7 and 28 days. This method of treatment caused a reduction in the swelling potential and the reduction was increased with increasing percent stabilizers.

Submitted by Maria Beatriz Vieira (mbeatriz.vieira@gmail.com) on 2017-03-17T12:23:54Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_paulo_eduardo_rocha_eberhardt.pdf: 1985819 bytes, checksum: bed6d72ca6a80b32c05abe648c7fd3d5 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-03-17T22:21:54Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_paulo_eduardo_rocha_eberhardt.pdf: 1985819 bytes, checksum: bed6d72ca6a80b32c05abe648c7fd3d5 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-03-17T22:22:51Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_paulo_eduardo_rocha_eberhardt.pdf: 1985819 bytes, checksum: bed6d72ca6a80b32c05abe648c7fd3d5 (MD5) / Made available in DSpace on 2017-03-17T22:23:00Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_paulo_eduardo_rocha_eberhardt.pdf: 1985819 bytes, checksum: bed6d72ca6a80b32c05abe648c7fd3d5 (MD5) Previous issue date: 2015-02-26 / Sem bolsa / O arroz (Oryza sativa L.) é um dos cereais mais cultivados, especialmente na Ásia onde concentra 90% da produção e consumo mundial de arroz. A qualidade das sementes é determinada por fatores físicos, genéticos, fisiológicos e sanitários. O objetivo foi avaliar o comportamento de sementes de arroz durante o armazenamento e o uso de pós de rocha no recobrimento de sementes. O trabalho foi conduzido na Universidade Federal de Pelotas no ano agrícola 2013/2014. As sementes foram recobertas por dois pós de rocha sendo um granodiorito e um basalto nas doses de zero, 7,5%, 15% e 30% de pó de rocha e armazenadas por doze meses. A cada dois meses foram realizados os testes de germinação, primeira contagem de germinação, envelhecimento acelerado, teste de frio, comprimento de raiz, comprimento de parte aérea e teor de água. No mês de outubro, período de semeadura da cultura foi realizado os testes de emergência em areia, índice de velocidade de emergência e matéria seca de plântulas. Pode-se observar que o recobrimento de sementes com pós de rocha proporcionaram maior germinação, melhor desempenho no teste de frio, maior comprimento de parte aérea e redução no teor de umidade de sementes. O recobrimento proporcionou também maiores índices de velocidade de emergência e matéria seca de plântulas em relação as sementes não tratadas. / Rice (Oryza sativa L.) is one of the most cultivated cereals, especially in Asia where it concentrates 90% of world production and consumption of rice. The seed quality is determined by physical, genetic, physiological and health. The objective was to evaluate the rice seed storage behavior and the use of rock in the post seed coating. The work was conducted at the Federal University of Pelotas in the agricultural year 2013/2014. The seeds were coated with two rock powders being one granodiorite rock and basalt in the untreated seeds and the doses, 7.5%, 15% and 30% of rock dust, and stored for twelve months. Every two months were performed by standard germination, first count of germination, accelerated aging, cold test, root length, shoot length and water content. In October, crop sowing period was evaluated emergence test in sand, emergency speed index and seedling dry. It can be observed that the coating of seeds with rock powders showed higher germination, improved performance in the cold test, increased shoot length and reduction in moisture content of the seeds. The coating also provided higher speed of emergence index and seedling dry over the untreated seeds.