The use of light-weight building materials in modern construction has resulted in efficient designs and considerable cost savings by reducing structural weight and supporting sections. This has only been possible because of many years of research to better understand the properties of the light-weight material, and its structural behaviors. However, light-weight grout is a relatively new building material in reinforced masonry construction and little is known about its structural properties. The main objective of this study was to determine if the use of light-weight grout would impact the performance of reinforcing steel, specifically development length, in masonry construction.The research included testing masonry wallettes made with normal and light-weight grout containing No. 4 (12 mm) bars with splice lengths as prescribed by the current design equation as well as splices with a modification factor. The modification factor was based on preliminary grout testing, using the procedure given in the concrete building code. The wallettes were tested in a tension test to determine if the splices were of sufficient length to fully develop the yield stress of the reinforcement.For small bar sizes, No. 4 or smaller, it is not necessary to include a modification factor when calculating development length. The minimum length of lap of 12 in. governs when No. 4 or smaller bars are used, and provides sufficient length to fully develop the yield stress of the reinforcement both for normal and light-weight grout types.

No description available.

A set of experimental tests were performed at Virginia Tech to investigate transverse joints and blockouts on full depth concrete bridge deck panels. The joints were designed on a deck replacement project for a rural three span continuous steel girder bridge in Virginia. Two cast-in-place and four post-tensioned joints were designed and tested in cyclical loading. Each joint was tested on a full scale two girder setup in negative bending with a simulated HS-20 vehicle. The blockouts were built as hollow concrete rings filled with grout and left to shrink under ambient conditions. Thirteen combinations of different surface conditions and grouts were designed to test the bond strength between the materials. The strain profile, cracking patterns, and ponding results were measured for all specimens. A finite element analysis was performed and calibrated with the laboratory results. The cast-in-place joints and the two post-tensioned joints with 1.15 MPa (167 psi) of initial stress experienced cracking and leaked water by the end of the tests. The two post-tensioned joints with 2.34 MPa (340 psi) initial stress kept the deck near a tensile stress of 1.5√(𝑓'c) and performed the best. These transverse joints did not leak water, did not have full depth cracking, and maintained a nearly linear strain distribution throughout the design life. Full depth deck panel may be effectively used on continuous bridges if a sufficient amount of post-tensioning force is applied to the transverse joints. The finite element model provides a design tool to estimate the post-tensioning force needed to keep the tensile stresses below the cracking limit. The blockouts with a roughened surface or an epoxy and a grout equivalent to Five Star Highway Patch grout had the highest bond stresses, did not leak water, and had smaller cracks at the grout-concrete interface than the control samples. A minimum bond strength of 2.5√(𝑓'c) was maintained for all of the specimens with a grout equivalent to Five Star Highway Patch. A pea gravel additive in the grout reduced shrinkage and reduced the bond strength. The finite element model provides a design tool to estimate cracking at the grout-surface interface. / Ph. D.

The use of full-depth precast concrete bridge deck panels is becoming more and more attractive to transportation authorities throughout the country. In comparison to conventional cast-in-place decks, precast decks are of higher quality, allow for the bridge to be opened to traffic in less time and are easier to maintain, rehabilitate, and replace. This ultimately results in lower costs for transportation authorities and less disruption for the motoring public. Unfortunately, the use of precast deck panel systems is hindered by the lack of design standardization and information regarding the performance of such systems. This research focuses on a key element of the system, the mortar or grout, which is used to connect the precast panels to the bridge girders by filling the space in the horizontal shear pockets and the haunches. Several essential mortar characteristics were identified and investigated in order to create a specification that indicates required performance criteria for mortars. This specification can be used to determine whether particular mortars or grouts are suitable for use in a full-depth precast concrete bridge deck panel system. / Master of Science

Chemical grouting has been used to insure the stability of underground mine openings for more than twenty years. The polyurethane grout, which is currently being used, has a limited range of mechanical properties that restrict its utilization. Polyurethane also poses serious threats to miners' health due to its toxicity and flammability, To overcome many of these problems and limitations, research has been conducted on a newly developed polyester-based grout. The assessment of mechanical properties of polyester grout is the focus of this work. Field experiences and laboratory research have defined properties which an effective grouting material should possess. Experimental results indicate that the polyester grout meets or exceeds these recommended properties and has the potential to expand the applicability of chemical grouting in ground control. By adjusting its formulations, mechanical properties of polyester grout can be engineered to solve specific ground control problems. / Master of Science

Este trabalho apresenta uma revisão bibliográfica a respeito dos rejuntes para revestimento cerâmico. A nomenclatura internacional é explorada e os tipos de rejunte e seus empregos são enumerados. Para embasar o leitor sobre o reves-timento cerâmico, os principais conceitos a ele relacionados são exibidos de forma sucinta. Uma vez que o rejunte é um componente importante do revestimento ce-râmico, suas funções dentro desse subsistema são abordadas em detalhes. O as-pecto de alívio de tensões é amplamente comentado, uma vez que essa é uma função essencial do rejunte, particularmente no caso de fachadas. Ao final, são abordados os aspectos de preparo e aplicação dos rejuntes, particularmente os produtos cimentícios. O rejuntamento de locais específicos, como encontros com selantes e interfaces com aparelhos sanitários são detalha-dos com vistas à diminuição da ocorrência de manifestações patológicas futuras. No trabalho experimental, painéis em forma de laje revestidos com placas cerâmicas são submetidos à flexão até a ocorrência de desplacamento, objeti-vando detectar qual a influência da largura da junta e do tipo de argamassa ade-siva na ruptura do corpo-de-prova. Os resultados indicam que a largura das juntas de assentamento assumem importância apenas quando a argamassa adesiva apresenta alta resistência de aderência. / This study presents a bibliographical revision regarding the ceramic tile grouts. Here, the international nomenclature is explored and the types of grouts as well as its employments are enumerated. To base the reader on the ceramic tile cladding, its main concepts are shown succinctly. Being the grout an important component of the ceramic tile cladding, its functions in this subsystem are broached in details. The aspect of stress relief is widely mentioned, for this is an essential function of grout, particularly in the case of facades. In the end, the aspects of the preparation and the application of grouts are broached, particularly the cementitious products. The grouting of specific places such as meetings of sealants and interfaces with sanitary devices is detailed viewing the decrease of the occurrence of future problems. In the experimental study, panels in flagstone form tiled with ceramic plates are submitted to flexion until the occurrence of rupture of these panels, aiming to detect the influence of the joint thickness and of the type of the adhesive mortar in the rupture of the sample. The results indicate that the nesting joint thickness only assumes importance when the adhesive mortar presents high resistance of adherence.

Este trabalho apresenta uma revisão bibliográfica a respeito dos rejuntes para revestimento cerâmico. A nomenclatura internacional é explorada e os tipos de rejunte e seus empregos são enumerados. Para embasar o leitor sobre o reves-timento cerâmico, os principais conceitos a ele relacionados são exibidos de forma sucinta. Uma vez que o rejunte é um componente importante do revestimento ce-râmico, suas funções dentro desse subsistema são abordadas em detalhes. O as-pecto de alívio de tensões é amplamente comentado, uma vez que essa é uma função essencial do rejunte, particularmente no caso de fachadas. Ao final, são abordados os aspectos de preparo e aplicação dos rejuntes, particularmente os produtos cimentícios. O rejuntamento de locais específicos, como encontros com selantes e interfaces com aparelhos sanitários são detalha-dos com vistas à diminuição da ocorrência de manifestações patológicas futuras. No trabalho experimental, painéis em forma de laje revestidos com placas cerâmicas são submetidos à flexão até a ocorrência de desplacamento, objeti-vando detectar qual a influência da largura da junta e do tipo de argamassa ade-siva na ruptura do corpo-de-prova. Os resultados indicam que a largura das juntas de assentamento assumem importância apenas quando a argamassa adesiva apresenta alta resistência de aderência. / This study presents a bibliographical revision regarding the ceramic tile grouts. Here, the international nomenclature is explored and the types of grouts as well as its employments are enumerated. To base the reader on the ceramic tile cladding, its main concepts are shown succinctly. Being the grout an important component of the ceramic tile cladding, its functions in this subsystem are broached in details. The aspect of stress relief is widely mentioned, for this is an essential function of grout, particularly in the case of facades. In the end, the aspects of the preparation and the application of grouts are broached, particularly the cementitious products. The grouting of specific places such as meetings of sealants and interfaces with sanitary devices is detailed viewing the decrease of the occurrence of future problems. In the experimental study, panels in flagstone form tiled with ceramic plates are submitted to flexion until the occurrence of rupture of these panels, aiming to detect the influence of the joint thickness and of the type of the adhesive mortar in the rupture of the sample. The results indicate that the nesting joint thickness only assumes importance when the adhesive mortar presents high resistance of adherence.

Preplaced aggregate concrete (PAC) is produced by grouting high workability cement based grouts among the voids of compacted coarse aggregate mass. Because of its low shrinkage, PAC has been used for many repair jobs like; tunnel lines, dams and bridge piers. Moreover, it has been used for underwater construction. Grout has a major effect on the properties of produced PAC and well defined grout controls the properties of resulted PAC. The effect of types and amount of powder materials, admixtures, sand and water content on the properties of fresh and hardened grout for the production of PAC have been investigated. Tests on hardened grout and PAC properties have also been carried out to investigate the most important effects. A correlation between hardened properties of grout and PAC has also been analyzed. Grout rheology using four different gradation sands at two different cement-sand and at different w/c ratios ratios has been identified experimentally; no added chemical admixtures or mineral additives had first employed, then superplasticizer (SP) was added at 2% and 1%, and finally a combination of 1% SP and pulverized fuel ash (Pfa) at 20% of the cement weight was employed for all mixes. Grout tests have included two point workability tests by the Viskomat NT, flow time funnel test, Colcrete flow meter test, and water bleeding test. After that, eighteen grout mixes with high workability were produced using three different sands at three w/c ratios and two c/s ratios with 1% SP and Pfa at 20% of the cement weight were designed. Eighteen hardened grout and PAC then produced and their compressive strength and sorptivity were tested. Grout rheology can be defined by the rheology of cement paste employed and the internal distance between sand particles. The effect of sand surface texture on grout rheology is important at very low internal distances. Fresh grout yield stress is the most important property which gives the same degree of sensitivity for all grouts regardless the material type and content used in the mix. There are strong relations between compressive strength of grout and PAC, but less correlation between them in sorptivity test because of the effect high quantity of coarse aggregate of PAC. Sorptivity of PAC is low comparing with different kinds of concrete suggesting its advantage for underwater construction.

In the past centuries, grouting has been one of the most common techniques in geotechnical engineering to strengthen and seal underground structures. Concerning increasing demands for tightness and cost efficiency, cement-based grout has been one the most frequent used materials. One of the first grouting operations is the work done by Charles Bérigny in France back in 1802 in order to repair a sluice by stabilizing the ground with liquid grout. Several studies have been then conducted in grouting, which have contributed into successful improvement of the grouting operations. The investigations have also extended the understanding of the factors such as choice of materials, choice of equipment, and the applied pressure type and magnitude, etc. that influencing the grout spread in rock fracture systems.   Among the factors, the applied pressure is one of the most significant ones influencing the spread of grout during grouting operations. Grouting at static pressure conditions is the most common method used in field, where in practice the injected grout can only penetrate into the rock fractures wider than 100 µm.   Recent investigations conducted on application of static and dynamic pressure conditions, using Short Slot and Varying Aperture Long Slot (VALS) in the lab have yielded an overall improvement of the grout spread under dynamic pressure conditions rather than the conventional static pressure conditions. However, the efforts conducted are just a beginning, especially in very fine micro factures smaller than 70 µm    The main objective of this investigation was therefore to improve the spread of grout by dynamic grouting into fractures smaller than 70 µm effectively, which could not be done with grouting at static pressure conditions.  Furthermore, the aim was to investigate filtration and erosion phenomena/ tendency of grout flow during static and dynamic pressure application using Varying Aperture Long Slot (VALS) in the lab. The durations of peak and rest periods used in the experiments were 2s/2s and 1s/5.5s, which were equivalent to 0.25 Hz and 0.15 Hz, respectively. The results of dynamic grouting showed up to 10 times improvement in the volume of passed grout through fracture apertures smaller than 70 µm. / Injektering är en av de vanligaste metoderna som använts för att förstärka och täta geotekniska konstruktioner. När det gäller ökande krav på täthet och kostnadseffektivitet har cementbaserade bruk varit ett populärt förbrukningsmaterial. Injektering användes förmodligen först av Charles Bérigny i en slussreparation i Frankrike under 1802 där marken stabiliserades med hjälp av flytande injekteringsmaterial. Flera studier har sedan dess utförts inom injekteringsteknik, vilket har bidragit till en framgångsrik förbättring av injekteringsoperationer. Dessa undersökningar har också utvidgat förståelsen av faktorer såsom materialegenskaper, val av utrustning, provprestanda, trycktyp och storhet som i sin tur påverkar brukets spridningsförmåga i bergets spricksystem.   Forskningen inom bergtätning fokuserar bland annat på att utveckla tillämpningen av statisk och dynamisk tryck vid injektering. Tillämpning av statiskt tryck är den vanligaste metoden för injektering ute i arbetsfält, där den injicerade bruket i praktiken endast kan tränga in i bergssprickor som är större än 100 μm.   De senaste undersökningarna med hjälp av Short Slot och Varying Aperture Long Slot (VALS) har visat en övergripande förbättring av inträngningen under dynamisk injektering jämfört med de konventionella statiska. Detta är bara en början och metoden behöver utvecklas mer, särskild för att åstadkomma bruksspridningen i mycket finare mikrosprickor, exempelvis sprickor mindre än 70 µm.   Syftet med detta arbete var att utveckla injekteringsmetoden där bruket kan tränga  i berg med sprickor mindre än 70 µm. Resultaten på de dynamiska tryckförhållanden visade att injekteringsbruket trängde bättre  i de smala sprickor  jämfört med de statiska tryckförhållanden. Upp till 10 gånger mer mängd av injekteringsbruk passerade sprickor med storlek mindre än 70 µm i VALS. Vidare har inloppsflödet och filtrerings- och erosionsfenomenen studerats med hjälp av laboratorieinstrumentet VALS. Varaktigheten av peak- och restperioder som användes i experimenten var 2s/2s och 1s 5.5s, vilka var ekvivalenta med 0.25 Hz respektive 0.15 Hz.

Preplaced aggregate concrete (PAC) is produced by grouting high workability cement based grouts among the voids of compacted coarse aggregate mass. Because of its low shrinkage, PAC has been used for many repair jobs like; tunnel lines, dams and bridge piers. Moreover, it has been used for underwater construction. Grout has a major effect on the properties of produced PAC and well defined grout controls the properties of resulted PAC. The effect of types and amount of powder materials, admixtures, sand and water content on the properties of fresh and hardened grout for the production of PAC have been investigated. Tests on hardened grout and PAC properties have also been carried out to investigate the most important effects. A correlation between hardened properties of grout and PAC has also been analyzed. Grout rheology using four different gradation sands at two different cement-sand and at different w/c ratios ratios has been identified experimentally; no added chemical admixtures or mineral additives had first employed, then superplasticizer (SP) was added at 2% and 1%, and finally a combination of 1% SP and pulverized fuel ash (Pfa) at 20% of the cement weight was employed for all mixes. Grout tests have included two point workability tests by the Viskomat NT, flow time funnel test, Colcrete flow meter test, and water bleeding test. After that, eighteen grout mixes with high workability were produced using three different sands at three w/c ratios and two c/s ratios with 1% SP and Pfa at 20% of the cement weight were designed. Eighteen hardened grout and PAC then produced and their compressive strength and sorptivity were tested. Grout rheology can be defined by the rheology of cement paste employed and the internal distance between sand particles. The effect of sand surface texture on grout rheology is important at very low internal distances. Fresh grout yield stress is the most important property which gives the same degree of sensitivity for all grouts regardless the material type and content used in the mix. There are strong relations between compressive strength of grout and PAC, but less correlation between them in sorptivity test because of the effect high quantity of coarse aggregate of PAC. Sorptivity of PAC is low comparing with different kinds of concrete suggesting its advantage for underwater construction. / Libyan High Education Ministry