Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1895. / The entire thesis text is included in file. Holograph [Handwritten and illustrated in entirety by author]. Title from title screen of thesis/dissertation PDF file (viewed January 29, 2009)

This research fully use the absorbability extremely good characteristic of bamboo charcoal, probe into the feasibility research that the bamboo charcoal will be applied to the ocean engineering. The bamboo charcoal with replace different thin aggregates weight¡]replace 0%¡B3%¡B5% and 7% of thin aggregates weight¡^add it into the cement mortar, and then to plan three kinds of cement mortar ratio¡]w/c=0.40¡B0.48 and 0.55¡^,and test of every relevant tests. Include strength and permeability relevant tests, probe into bamboo charcoal is it influence engineering character of the cement mortar to add. In order to assess the suitability that the bamboo charcoal applies to the cement mortar, test this material replace part thin aggregates compression strength and permeability coefficient of the influence, and the bamboo charcoal to have absorbability the chlorine ion and sulfide harmful chemical of the characteristic to the bamboo charcoal. Test to resist chloride ion and sulfide tests, to discussion by the result of the test. In order to get a group of best cement mortar ratio of replace the bamboo charcoal, and change tiny structure of the cement mortar with Scanning Electron Microscope¡]SEM¡^. By prove feasibility to the ocean engineering the bamboo charcoal adds into the cement mortar.

No description available.

Many Canadian cities are faced with the problem of an aging and deteriorating iron water distribution network - pipe breaks, leakage, and/or aesthetic water quality problems. Public confidence in municipalities’ ability to deliver safe, clean drinking water to customers has been eroded, especially in areas of water distribution networks receiving coloured water events that result from the internal corrosion of aging iron watermains. Cement mortar lining is one of the most widely used non-structural watermain rehabilitation methods for the prevention of coloured water events due to internal iron pipe corrosion; however, it is also thought/claimed to be a means of controlling corrosion pin-hole leakage. This thesis presents the results of a laboratory testing program designed to investigate the renewal of potable watermains via the use of cement mortar lining. The specific focus of this thesis is the ability of the cement mortar lining to bridge corrosion pin-holes and prevent water loss from the watermain, and the effects of mortar application on the corrosion protection provided to the iron watermain by cement mortar lining. The results of this study are based on short term testing and do not consider fatigue. The ability to bridge corrosion pin-holes / water loss prevention laboratory testing program found that pressure should not be returned to a newly lined watermain until the lining has cured for a period of at least four days to prevent failures from occurring prior to the lining achieving sufficient strength characteristics if the lining is to be used as a structural rehabilitation technique. The cure time corrected normalized thickness at failure data was found to be a Gumbel distributed data set. The Gumbel distribution can be used to predict the lining thickness required to bridge a known corrosion pin-hole diameter with a set degree of confidence that failure will not occur. A 3 mm thick cement mortar lining can bridge a pin-hole 12.0 mm in diameter while a 5mm thick cement mortar lining can bridge a pin-hole 19.9 mm in diameter with a 95% probability that failure will not occur Through the corrosion prevention testing program it was determined that the thickness of the cement mortar lining does not affect the ability of the lining to prevent corrosion from occurring. This was determined for cast iron pipes which have been lined for a period of one year. It is recommended that corrosion potential testing be performed on cement mortar lined watermains that have been in service for a longer period of time to determine if this consistent over the life cycle of the cement mortar lined watermain.

Many Canadian cities are faced with the problem of an aging and deteriorating iron water distribution network - pipe breaks, leakage, and/or aesthetic water quality problems. Public confidence in municipalities’ ability to deliver safe, clean drinking water to customers has been eroded, especially in areas of water distribution networks receiving coloured water events that result from the internal corrosion of aging iron watermains. Cement mortar lining is one of the most widely used non-structural watermain rehabilitation methods for the prevention of coloured water events due to internal iron pipe corrosion; however, it is also thought/claimed to be a means of controlling corrosion pin-hole leakage. This thesis presents the results of a laboratory testing program designed to investigate the renewal of potable watermains via the use of cement mortar lining. The specific focus of this thesis is the ability of the cement mortar lining to bridge corrosion pin-holes and prevent water loss from the watermain, and the effects of mortar application on the corrosion protection provided to the iron watermain by cement mortar lining. The results of this study are based on short term testing and do not consider fatigue. The ability to bridge corrosion pin-holes / water loss prevention laboratory testing program found that pressure should not be returned to a newly lined watermain until the lining has cured for a period of at least four days to prevent failures from occurring prior to the lining achieving sufficient strength characteristics if the lining is to be used as a structural rehabilitation technique. The cure time corrected normalized thickness at failure data was found to be a Gumbel distributed data set. The Gumbel distribution can be used to predict the lining thickness required to bridge a known corrosion pin-hole diameter with a set degree of confidence that failure will not occur. A 3 mm thick cement mortar lining can bridge a pin-hole 12.0 mm in diameter while a 5mm thick cement mortar lining can bridge a pin-hole 19.9 mm in diameter with a 95% probability that failure will not occur Through the corrosion prevention testing program it was determined that the thickness of the cement mortar lining does not affect the ability of the lining to prevent corrosion from occurring. This was determined for cast iron pipes which have been lined for a period of one year. It is recommended that corrosion potential testing be performed on cement mortar lined watermains that have been in service for a longer period of time to determine if this consistent over the life cycle of the cement mortar lined watermain.

Thesis (Ph.D.)--Michigan State University. Dept. of Civil & Environmental Engineering, 2008. / Title from PDF t.p. (viewed on Apr. 2, 2009) Includes bibliographical references (p. 217-225). Also issued in print.

No / As the weakest zone in concrete, the interfacial transition zone (ITZ) between aggregates and cement mortars has important effects on the properties of concrete. This paper aims to investigate the effects and mechanisms of nanofillers on the bond strength and interfacial microstructures between aggregates and cement mortars. A total of 8 representative types of nanofillers (namely nano-SiO2, nano-TiO2, nano-ZrO2, untreated multi-walled carbon nanotubes (MWCNTs), hydroxyl-functionalized MWCNTs, nickel-coated MWCNTs, multi-layer graphenes (MLGs), and nano boron nitride (nano-BN)) were selected to fabricate specimens with scale-up aggregate-cement mortar interface that can be characterized by the three-point bend test. The experimental results indicate that all types of nanofillers can enhance the bond strength between aggregates and cement mortars. The highest relative/absolute increases of 2.1 MPa/35.1%, 2.32 MPa/38.8% and 2.56 MPa/42.8% in interfacial bond strength are achieved by incorporating 2 wt% of nano-ZrO2, 0.3 wt% of nickel-coated MWCNTs, and 0.3 wt% of nano-BN, respectively. Scanning electron microscope observations show the presence of nanofillers can improve hydration products and increase interfacial compactness. Energy dispersive spectrometer results suggest that local content of nanofillers in the ITZ is higher than that in the bulk cement mortars. These findings indicate the nanofillers can transfer with water migration toward aggregates and enrich in ITZ, thus improving the bond strength and interfacial microstructures between aggregates and cement mortars through the nano-core effect. / National Science Foundation of China (51978127 and 51578110), and the Fundamental Research Funds for the Central Universities in China(DUT18GJ203)

Since the introduction of Portland cement in the early nineteenth century the number of buildings constructed from concrete or using cement mortars and renders has grown exponentially, and cement is one of the most common building materials in use today. Consequently a significant proportion of the built heritage contains cementitious materials. The relative youth of these buildings means that less research has been undertaken to understand how and why they deteriorate than for traditional buildings, and that the development of appropriate conservation methods and techniques is less advanced. The primary aim of this research was to understand the causes and mechanisms of some of the types of deterioration commonly found in historic concrete and cement buildings and structures, with reference to the Second World War reinforced concrete and cement-rendered buildings at East Fortune airfield in East Lothian, Scotland. Additional aims were to investigate the efficacy of the building repairs and maintenance regimes undertaken to date, and to make recommendations for the future conservation of the buildings. East Fortune airfield contains a number of cement-rendered brick masonry buildings and a reinforced concrete air raid shelter. The initial visual survey identified several types of deterioration, from which the blistering and flaking of the render; the cracking and delamination of the render; and the spalling of the concrete in the air raid shelter were selected for further research. The research included time lapse photography, non-destructive testing, environmental monitoring and the physical, chemical and petrographic characterisation of the building materials. Hypotheses regarding the causes of deterioration were tested in the laboratory, for example with linear variable displacement transducer measurements, and modelled using crack propagation theories and models for water transport through porous media. It is demonstrated that the blistering and flaking of the render is caused by shale aggregate particles, which undergo sufficient expansion during freeze-thaw cycles to crack the surrounding render. This phenomenon is termed ‘pop-outs’ in the concrete literature. The more catastrophic cracking and delamination of the renders is also due to freeze-thaw cycling, which is shown to cause significant damage provided the moisture content of the render is above a certain threshold level. This type of deterioration has occurred at an accelerated rate for some of the modern render repairs, due to an inadequate understanding of the properties of the original and repair materials. In particular, the properties of the bricks are critical to the performance of the cement renders, and it is found that the sorptivity of historic bricks may vary considerably depending upon the orientation of the brick. Finally, the diagnosis for the air raid shelter is that the corrosion of the steel reinforcements is caused by high levels of chlorides present within the raw materials used to make the pre-cast concrete sections. The results of the investigations are used to suggest building conservation solutions for this particular site. Furthermore, since the deterioration mechanisms investigated are common for historic cement and concrete, the findings are relevant to many other sites. The over-arching methodology used to investigate the deterioration at the site and the methodologies developed to test particular hypotheses are also applicable for other investigations of historic building materials. There is much about this research that is innovative and new. The work on render cracking compares the results of dilation tests on cementitious and ceramic materials, which has not been done previously, and the pop-outs diagnosed in the work on render flaking have rarely, if ever, been reported for cement renders. The modelling work undertaken to quantify the stresses produced by the pop-outs and to explain the inclined crack formation patterns is entirely original. The use of petrography to diagnose causes of render failure is described in the literature, but this is one of very few case studies to be written up, and the work on the air raid shelter constitutes the only formal investigation of this type of Stanton shelter.

[pt] O objetivo deste trabalho foi a análise macro-mecânica do comportamento da terra como argamassa para revestimentos de terra. Não foram encontradas referências a estudos semelhantes a este, tratando-se portanto de um estudo pioneiro, no Brasil e no exterior. Os revestimentos foram aplicados em um substrato de terra batida de 50 e 30 cm de altura e de largura, respectivamente. Foram analisados revestimentos fabricados com 17,5%, 12%, 9% e 6% em peso de argila em relação ao material seco para dois solos distintos: Tassin (ilítico) e Rochechinard (caulinítico). Como revestimento de referência, foi fabricada uma argamassa de cal e areia (1:3). Além disso, foi avaliado o efeito da inclusão de duas fibras existentes no mercado: fibras curtas de sisal (Agave sisalana), naturais do Brasil, e resíduos de fabricação de fibras curtas de cânhamo (Cannabis sativa), provenientes da França. Tais fibras foram empregadas somente em corpos-deprova de Rochechinard com 17,5% e 12% em peso de argila em relação ao material seco, e adicionadas ao solo em uma porcentagem de 0,5% do peso do solo seco, com as mãos. Sisal possui seção circular com valores médios de 0,15 mm de diâmetro e 40 mm de comprimento; cânhamo é considerado como seção retangular de 2x5 mm de área e comprimento de 20 mm. Para todos os revestimentos foram realizadas observações visuais in situ da retração. Em seguida, os revestimentos foram ensaiados ao cisalhamento através da adição de 250 g, até a ruptura, a cada 30 s em um quadro retangular de madeira, que era pendurado nas amostras. No laboratório, a retração restringida em 4 lados e a resistência à flexão foram testadas em amostras prismáticas. Foi observado que tanto a retração quanto a resistência à flexão aumentam com o teor de argila. Além disso, os compósitos de solo com sisal apresentaram, em geral, maiores resistências àqueles em que houve emprego de cânhamo. / [en] This work analyzes the macro-mechanical behavior of earth when it is used as a raw material for finishing. It is a pioneer study in Brazil and abroad. The finishings were applied on a rammed earth wall of 50 of height and 30 cm of width. Finishings fabricated with four different clay contents (17,5%, 12%, 9% and 6% by weight of clay in relation to the dry material) were analyzed for two different soils. Each one of these soils has a predominant type of clay: Tassin (with illite in greater quantity) and Rochechinard (with kaolinite in greater quantity). As a reference finishing, it was fabricated a mortar of lime and sand (1:3). Furthermore, the behavior of two fibers was evaluated: short sisal fibers (Agave sisalana), natural from Brazil, and residue from the manufacture of short hemp fibers (Cannabis sativa), from France. These fibers were used only in samples of Rochechinard with two clay contents (17.5% and 12% by weight of clay in relation to the dry material). The fibers were added to the soil on a percentage of 0.5% by weight of dry soil, manually. Sisal has circular section with average values of 0.15 mm of diameter and 40 mm long; hemp fiber is considered as a rectangular section with 2 mm of height, 5 mm of width and 20 mm long. For all finishings, visual observations of shrinkage were performed in situ. Those finishings with higher clay content dropped from the support. The finishings which did not fell were tested in shear. For this, a load of 250 g was added, until rupture, in every 30s on a rectangular wood frame (600 g weight), that was hung in the samples. In laboratory, linear shrinkage and flexural strength were tested on prismatic samples. It was observed that both shrinkage and flexural strength increase with clay content. Regarding the addition of fibers, it was found that the composites fabricated with sisal had generally better results than those with hemp.

[pt] A presente tese estuda as propriedades de curta e londa duração de argamassas de cimento reforçadas com fibras de coco e sisal. O trabalho experimental visou a determinação das propriedades físicas e mecânicas do reforço e o estudo da influência do tipo, fração volumétrica e tamanho de fibra, orientação e composição da matriz nas propriedades mecânicas do compósito. Estudos foram executados com o objetivo de se determinar a influência do reforço na retração plástica, com e sem restrições, das matrizes de argamassa. Fissurações resultantes da imposição das restrições e o fenômeno de cicatrização das fissuras foram também investigados. O modo de ruptura e as propriedades de aderência interfacial fibra-matriz foram determinados através de ensaios de arrancamento. As propriedades de longa duração dos compósitos foram determinadas através dos ensaios de fluência, retração e durabilidade. A influência da adição de várias frações volumétricas e tamanhos de fibras na fluência das matrizes de argamassa foi determinada usando-se corpos de prova, selados e não selados, submetidos a uma pressão de 14,4 MPa durante um período de 210-350 dias. Recuperações das deformações elásticas foram monitoradas por um período de 56-180 dias. A influência dos tipos de fibra, fração volumétrica, tamanho de fibra, tipo de cura, traço da argamassa e substituição parcial do cimento Portland por micro-sílica e escória de alto forno na estabilidade dimensional das matrizes de argamassa foi determinada com o uso de ensaios de retração por um período de 320 dias. A durabilidade das fibras de coco e sisal, imersas em soluções alcalinas de hidróxido de cálcio e de sódio e em água de torneira, foi determinada através da realização de ensaios de resistência à tração em idades variando de 30-420 dias. A durabilidade das argamassas reforçadas com fibras naturais após 320-360 dias imersas em água, expostas a ciclos de molhagem e secagem bem como ao ambiente natural foi determinada através de resultados de ensaios de flexão e de observações de imagens obtidas com o uso de microscopia eletrônica. Um mapeamento de elementos químicos foi realizado com o objetivo de se verificar possíveis migrações de produtos da matriz de cimento Portland para o lúmen e paredes das fibras. Tratamentos para garantir a durabilidade dos compósitos foram estudados, a saber: (a) modificações na matriz através da substituição parcial do cimento Portland por micro-sílica e escória de alto orno; (b) carbonatação da matriz de cimento Portland; (c) imersão das fibras em micro-sílica líquida antes de serem incorporadas à matriz de cimento Portand. / [en] This thesis studies both the short-term and long- term behaviour of sisal and coconut fibre reinforced mortar composites.The experimental work involved extensive laboratory testing to determine the physical and mechanical properties of the fibre reinforcement and to study the influence of fibre type, volume fraction, fibre length, fibre arrangement and matrix composition on the mechanical properties of the composite.Studies were also made to determine the influence of fibre reinforcement in controlling free and restrained shrinkage during the early age of mortar mixes. Cracking due to restraint and the phenomenon of crack self-healing were also investigated. The mode of failure and the properties of the resistance to fibre-matrix interfacial bonding were determined using the single fibre pull-out test.The long-term properties of the sisal and coconut fibre reinforced-mortar composites were assessed throughout creep, shrinkage and durability tests. The influence of the addition of sisal and coconut fibres, of various volume fraction and lengths, on the creep of a mortar matrix was determined using sealed and unsealed specimens subjected to a pressure of 14.4 MPa over a period of 210-350 days. Recovery strains were recorded for a period of 56-180 days.The influence of fibre types, volume fraction, fibre lengths, cure types, mix proportions and replacement of OPC by slag and silica fume on the dimensional stability of mortar matrices was determined using drying shrinkage tests for a period of 320 days. The durability of sisal and coconut fibres exposed to alkaline solutions of calcium and sodium hydroxide and stored in tap water was measured as strength loss over a period of 420 days. The durability of fibre-reinforced mortars after 320 to 360 days, stored under water, exposed to cycles of wetting and drying as well as to the natural weather,was assessed from results of flexural tests and from observations of the photomicrographs obtained using backscattered imaging and secondary electron imaging. Dotting maps of chemical elements were obtained in order to verify possible migration of cement products from the matrix to the lumen and voids within of the fibres. Treatments to enhance the durability performance of the composites were studied,including: (a) modifications to the matrix through the replacement of Portland cement by undensified silica fume and by blast-furnace slag; (b) carbonation of the cementitious matrix and (c) immersion of the fibres in slurry silica fume prior to being incorporated into the Portland cement matrix.