During the late eighteenth and throughout the nineteenth century masonry technology underwent a major transition, whereby, the production process increasingly absorbed techniques traditionally carried out by craftsmen. This transition also involved an increasing shift from lime technology to cement technology1. This influenced traditional work methods involving lime mortars as well as creating new methods for preparation of cement. Development of cement assisted the expansion of vital infrastructure such as roads, bridges, dams, sewers, and high-rise structures. In order to facilitate high-rise construction with cement, masonry units such as commercially produced brick were developed with similar strength and compression characteristics as cement. Historically, lime mortar preparation involved multiple and variant treatment methods. These practices arose from generations of experimental practice, in order to determine which methods were most beneficial. Development of these skills was transferred from master to apprentice and from father to son. These treatment methods involved a calcium carbonate raw material and its conversion into a lime suitable for blending with aggregates, which resulted in a workable mortar for uniting building materials. Such lime building compounds included, stuccos, frescos, plasters, and mortars. The scope of this project involves primarily lime mortar, although treatment methods and materials are very similar for all of these five lime compounds. Restoration of historic structures built with lime mortar creates challenges for architects, conservators, masons and all persons tasked with masonry restoration. Original masonry Materials and methods involving lime technology have been superseded by cement technology with its own materials and techniques. Cement has failed to provide a successful role as a binder for the restoration of historic structures built with lime mortar. In order to maintain the integrity of historic structures, rediscovery and application of traditional lime technology can further bridge the gap between past and present masonry mortar. / Master of Science

Many pavement subgrades in Virginia consist of wet, highly plastic clay or other troublesome soils. Such soils can be treated with traditional lime and cement stabilization methods. Alternatives, including lignosulfonates and polymers, are available, but their performance record is mixed and solid engineering data is lacking, which prevents reliable design. The goal of this research was to screen a suite of traditional and non-traditional stabilizers against three Virginia soils that have caused problems during construction or resulted in poor performance in service. The selected stabilizers were: quicklime, hydrated lime, pelletized lime, cement, lignosulfonate, synthetic polymer, magnesium chloride, and a proprietary cementitious stabilizer. A laboratory procedure was developed and applied to three Virginia soils obtained from Northern Virginia, Staunton, and Lynchburg. Key findings from the research include that (1) traditional lime and cement stabilizers were far more effective than liquid stabilizers (lignosulfonate, synthetic polymer, and magnesium chloride) in increasing strength, (2) the liquid stabilizers were ineffective on soils with high moisture content, (3) the proprietary cementitious stabilizer was more effective in increasing strength than lime for all cases tested, but not was not as effective as the cement stabilizer, (4) quicklime and hydrated lime increased workability of the soils although they did not produce strengths comparable to cement, (5) the strength of soils stabilized with cement and the proprietary cementitious stabilizer can be estimated based on the water-amendment ratio of the mixture, and (6) the strength of soils stabilized with lime can be estimated based on a combination of plasticity index and water-amendment ratio of the mixture. / Master of Science

Modification of black cotton soils by chemical admixtures is a common method for stabilizing the swell-shrink tendency of expansive soils. Advantages of chemical stabilization are that they reduce the swell-shrink tendency of the expansive soils and also render the soils less plastic. Among the chemical stabilization methods for expansive soils, lime stabilization is most widely adopted method for improving the swell-shrink characteristics of expansive soils. Lime stabilization of clays in field is achieved by shallow mixing of lime and soil or by deep stabilization technique. Shallow stabilization involves scarifying the soil to the required depth and lime in powder or slurry form is spread and mixed with the soil using a rotovator. The use of lime as deep stabilizer has been mainly restricted to improve the engineering behaviour of soft clays Deep stabilization using lime can be divided in three main groups: lime columns, lime piles and lime slurry injection. Lime columns refer to creation of deep vertical columns of lime stabilized material. Lime piles are usually holes in the ground filled with lime. Lime slurry pressure injection, as the name suggests, involves the introduction of a lime slurry into the ground under pressure. Literature review brings out that lime stabilization of expansive clays in field is mainly performed by mixing of lime and soil up to shallow depths. The use of lime as deep stabilizer has been mainly restricted to improve the engineering behaviour of soft clays. Use of lime in deep stabilization of expansive soils however has not been given due attention. There exists a definite need to examine methods for deep stabilization of expansive soils to prevent the deeper soil layers from causing distress to the structures in response to the seasonal climatic variations. In addition, there exists a need for in-situ soil stabilization using lime in case of distressed structures founded on expansive soil deposits. The physical mixing of lime and soil in shallow stabilization method ensures efficient contact between lime and clay particles of the soil. It however has limitation in terms of application as it is only suited for stabilization of expansive soils to relatively shallow depths. Studies available have not compared the relative efficiency of the lime pile technique and lime-soil mixing method in altering the physico-chemical, index and engineering properties of expansive black cotton soils. To achieve the above objectives laboratory experiments are performed that study: 1. the efficacy of lime piles in stabilizing compacted black cotton soil specimens from Chitradurga District in Karnataka. The efficiency of lime piles in chemically stabilizing the compacted black cotton soil mass was investigated as a function of: a)amount of lime contained in the lime pile b)radial migration of lime from the central lime pile c)migration of lime as a function of soil depth 2. the relative impact of the lime pile technique and lime-soil mixing method in altering the physico-chemical, index and engineering properties of expansive black cotton soil. The organization of this thesis is as follows After the first introductory chapter, a detailed review of literature performed towards highlighting the need to examine stabilization of expansive soils using lime pile technique is brought out in Chapter 2. Chapter 3 presents a detailed experimental programme of the study. 25 mm and 75 mm diameter lime piles were installed in the compacted soil mass to study the influence of amount of lime contained in the lime pile on the soil properties. The amount of quick lime contained in the 25 mm and 75 mm lime piles corresponded to 1 % and 3 % by dry weight of the soil mass respectively. Radial and vertical migration of lime from the central lime pile was examined by sampling soil specimens at different radial distances from the central lime pile and at different depths of soil sample. At a given depth and radial distance, migration of lime was estimated by comparing the exchangeable cation composition, pH and pore salinity of the treated soil with that of the natural (untreated) black cotton soil specimen. Alterations in the soil engineering properties at a given depth and radial distance were evaluated by comparing the index properties, swell potential and unconfined compressive strength of the lime pile treated soil specimen with those of the untreated specimen. To compare the relative efficiency of lime mixing and lime pile technique in altering the swelling behaviour of black cotton soil, batches of black cotton soil specimens were treated with 1 % and 3 % quick lime on dry soil weight basis. The compacted soil-lime mixes were cured at moisture contents of 31-34 % for a period of 10 days. The physico-chemical, index and engineering properties of the 1 % lime mixed specimens are compared with those of the 25 mm lime pile treated specimens. The properties of the 3 % lime mixed soil specimens are compared with those of the 75 mm lime pile treated specimens. Chapter 4 examines the efficacy of lime piles in stabilizing compacted black cotton soil specimens from Chitradurga District in Karnataka. Experimental results showed that controlling the swell potential of deep expansive soil deposits is possible by the lime pile technique. Treatment with lime pile caused migration of dissociated calcium and hydroxyl ions into the surrounding soil mass. In case of 25 mm lime pile, the experimental setup allowed measurement of migration of lime up to three times the lime pile diameter. In case of 75 mm lime pile, the experimental setup allowed measurement of migration of lime up to 1.6 times pile diameter. In both experiments, migration of lime was also uniform through out the soil depth of 280 mm. Migration of calcium and hydroxyl ions increased the pore salinity and pH of the treated soil mass. The increase in pH caused clustering of additional exchangeable calcium ions at the negative clay particle edges. The increased pore salinity and exchangeable calcium ions reduced the diffuse ion layer thickness that in turn suppressed the plasticity index and the swell potential of the compacted expansive soil. The laboratory results hence bring out that lime pile treatment in the field can substantially reduce the swell potential of the soil at least to a radial extent of 2 to 3 times the lime pile diameter. The 75 mm lime pile contained lime content in excess of the initial consumption of lime (ICL) value of the black cotton soil - namely 2.6 %. Laboratory results showed that migration of hydroxyl ions even from the 75 mm pile could not elevate the soil pH to levels required for soil-lime pozzoIonic reactions (pH ≥12). The very low solubility of lime in water (< 1 g/litre) and the impervious nature of the black cotton soil are considered to have impeded efficient interactions between lime and soil in course of treatment of the expansive soil with lime piles. Absence of soil-lime pozzolonic reactions precluded the formation of cementation compounds in the lime pile treated soil specimens. Cementation compounds formed by the soil-lime pozzolonic reactions are responsible for the much higher strengths of lime stabilized soils. Consequently, treatment with 25 mm pile had no impact on the unconfined compressive strength of the black cotton soil. Comparatively, treatment with 75 mm lime pile slightly increased the strength of the treated soil due to increased inter-particle attraction and particle flocculation. Chapter 5 compares the relative efficiency of the lime pile technique and lime-soil mixing method in altering the physico-chemical, index and engineering properties of expansive black cotton soil. Experimental results showed that mixing of soil and lime promote stronger chemical interactions between lime released hydroxyl ions and clay particles than that achieved by diffusion of lime from a central lime pile. The more alkaline pH of the lime mixed soil specimens rendered the clay particle edges more negative. Consequently, more calcium ions were adsorbed at the clay particle edges of the lime mixed soil specimens imparting them higher exchangeable calcium contents than the lime pile treated soil specimens. Also, at 3 % lime addition, the pH of the lime-mixed soil was sufficiently high (in excess of 12) to cause dissolution of silica and alumina from the clay lattice necessary for the formation of cementation compounds. The stronger lime modification reactions plus the lime-soil pozzolonic reactions (applicable for soil treated with lime content greater than ICL value) achieved by the lime mixing technique rendered the expansive soil much less plastic, much less expansive and much stronger than the lime pile treated specimens. The results of the laboratory study hence suggest that if a choice exists in the field between conventional method of spreading-mixing-compacting of soil-lime mixes and treating the ground with lime piles, the former technique should be adopted because of its greater efficacy in stabilizing the expansive soil. Chapter 6 summarizes the findings of the study.

Kalkbruk har använts i tusentals år som byggnadsmaterial i byggkonstruktioner.Senare, under 1800-talet, började en variant av hydraulisk kalk, kallad vattenkalk, att användas. Det hydrauliska kalkbruk som används idag i byggnadskonstruktioner såsom fasadmurning, putsning, fogning av murverk har blivit mer vanligt att använda i stället för cementbruk, eftersom det finns fler fördelar med kalkbruk som har hydraulisk inblandning än med det cementbaserade bruket. Kalkbruk används särskilt till renovering av äldre byggnader där kalk eller hydrauliska kalkbruk sedan tidigare har använts. Det hydrauliska kalkbruket utvinns från kalksten men den hydrauliska kalk som bränns av oren kalksten kallas naturligt hydraulisk kalk och tillverkas av Saint-Astier i Frankrike. Kalken har inga hydrauliska tillsatsmedel som cement, gips, flygaska eller puzzolana material. Enligt SS-EN 459–1:2015 klassas den naturliga hydrauliska kalken efter hållfasthet, och tillverkas i tre klasser: NHL 2, NHL 3,5 och NHL 5.Naturliga hydraulisk kalkbruken har för- och nackdelar, Produktens fördelar avses av de som använder bruket överväga nackdelarna. NHL-bruk passar bättre i fuktiga miljöer, det kan återanvändas, är miljövänligt, rent och naturligt, tål mer påfrestningar och driftstiden är mindre. Bakgrunden till arbetet är att NHL-bruks användning har blivit allt vanligare under de senaste decennier vid renovering av äldre kalkputsade byggnader. Väderförhållande och temperatur är av stor betydelse för att ha ett hållbart resultat inom kalkputsarbetet och således kan orsaka en viss försening i tidplaner och byggtider. Emedan nya metoder ska utreda och utvärderas för att få det optimala resultatet.Litteraturstudier, laboratorietester och intervjuer har använts för att kunna nå examensarbetets mål. Flera små tester har gjorts för att undersöka karbonatiseringsprocessen under olika väderförhållandet. Testerna visar att det naturliga kalkbruket karbonatiserar bättre och snabbare i en fuktig miljön, vilket passar det klimat som råder i Norden och i kustklimat. Det naturliga hydrauliska kalkbruket är dock ett material som kräver mer erfarenhet för att kunna uppnå bästa resultat för detta ändamål. Att vädret har stort betydelse för karbonatiseringsprocessen är ett resultat som framkommit i tidigare studier och forskning, vilket också de tester som utförts under detta arbete visar. Arbete med hydrauliska kalkbruk bör därför ske under perioder som passar kalkputsarbetet för att det ska hinna karbonatisera innan det riskerar att utsättas för påfrestning. En lämplig period är därför maj till oktober som den bästa perioder för kalkputsarbete.Naturliga hydrauliska kalkbruk utvecklas kontinuerligt, vilket kan bidra till att de kan ersätta det cementbaserade kalkbruket i framtiden utan några negativa konsekvenser såsom frostsprängning och låg hållfasthet. / The aim of the work was to analyze the carbonation of modern lime plaster with hydraulic mixing. Requirements for a certain carbonation can cause delays in schedules and construction time. The hydraulic lime mill is obtained from limestone, while the hydraulic lime burned by crude limestone is called natural hydraulic lime, which is manufactured by Saint-Astier in France. the lime has no hydraulic additives such as cement, plaster, fly ash or puzzolana materials. Natural Hydraulic lime mills fit better in the humid environment, it can be reused, is environmentally friendly, is clean and natural, can withstand more stress and the operating time is less. During the work, a study visit was made to an ongoing work process at Elin Wägnerskolan in Växjö, which Karlssons fasad AB had taken over the restoration responsibility. Interviews were conducted with one of the players at Målarkalk AB, which is one of the largest suppliers in the lime industry and project manager at Karlssons Fasad AB. Several small tests have been done to see the carbonation process under different weather conditions. The tests show that natural lime farming carbonates better and faster in a humid environment, which suits the Nordic countries and coastal environments. Natural hydraulic lime mills are well suited to replace cement-based mortars in the future without any negative impact.

Lime has been used in construction for millennia, and its value, especially in the field of conservation architecture, has only recently been rediscovered. Lime mortars harden through carbonation, and this thesis is a study of that process. The research conducted has resulted in the development of two novel techniques for the measurement and detection of carbonation. The first technique is a method of thermogravimetric analysis which allows the carbonation profile to be measured within an acceptable time-frame. The second technique is the use of drilling resistance measurement to visualise the carbonation profile. The potential of elemental analysis to measure the carbonation profile has also been identified. It has been demonstrated that the lime/water ratio has less impact on the compressive strength of air lime mortars than had previously been supposed. The change in the pore size distribution of air lime mortars caused by carbonation has been studied, and a theory has been proposed to explain this phenomenon. Five different forms of air lime binder were studied. The impact of these on the structural performance of the resultant mortars has been assessed. It was concluded that mortars made with lime putties perform better than mortars made with dry lime hydrate. Mortars made with dispersed hydrated lime appear to perform as well as mortars made with lime putties, but at a slower rate of strength growth. The use of extra mature lime putty does not appear to confer structural performance benefits when compared with ordinary lime putty. It has been shown that the use of calcitic aggregates can produce air lime mortars which perform as well as moderately hydraulic lime mortars. It is theorised that this phenomenon is not directly related to carbonation, but rather to a complex interaction of the granulometry, mineralogy, chemistry and porosity of the aggregate with the binder.

No description available.

No description available.

The first recorded use of hydraulic lime in construction can be traced back to at least two thousand years ago. Hydraulic lime, produced through either adding pozzolanic materials or calcining clay containing limestone, unlike air lime, can set and harden under water, developing strength through initial hydration reaction and subsequent carbonation. After WWII Portland cement mortars had almost completely replaced lime based mortars in modern construction. However, through conservation and specialist construction the benefits of hydraulic lime are becoming increasingly recognised. To support wider usage of these mortars there is a need for systematic study on the mortar properties and structural performance of lime mortared masonry. This thesis presents findings from a research programme conducted to develop understanding of the mechanical properties of natural hydraulic lime (NHL) mortared brickwork. The work focussed on the flexural strength of NHL mortared brickwork. A variety of material and environmental factors, including lime grade and supplier, mix proportion, sand type and age, have been investigated. In addition the research has completed an in-depth study on the influence of brick absorption characteristics on bond development. The two methods of flexural wall panel and bond wrench testing to establish flexural strength have been compared. In addition to flexural strength, initial shear strength and compressive strength of brickwork has also been investigated. A greater understanding of NHL mortared brickwork performance has been developed through this work. Performance of the brickwork has been related to properties of constituent materials and environmental factors. Recommendations for design performance of materials have been provided.

The world is facing increasing pressures to reduce the amount of energy and resources that are being used. The UK government has targets to reduce carbon emissions and energy usage. Within the UK buildings are a significant contributor towards both energy and material usage. One approach to reduce the energy and carbon emissions from construction is to use natural materials that require minimal processing and energy input such as straw, timber, unfired earth and hemp-lime. Hemp-lime is a composite solid wall insulating material made from hemp shiv and a lime based binder and water which can be cast between shutters or spray applied. Hemp-lime is typically used with a load bearing timber studwork frame. Current design practice assumes that hemp-lime is a nonstructural material and only provides the insulation to the wall construction. However, as it encapsulates the studs it has to potential to enhance their load capacity by preventing buckling and resisting in-plane forces. This study aimed to establish the contribution of the hemp-lime to the structural performance of composite hemp-lime and studwork frame walls under three loading conditions; vertical compression, in-plane racking and out-of-plane bending. Both theoretical analysis and experimental testing were undertaken in order to establish the contribution. Tradical HF hemp shiv and Tradical HB binder were used to mix hemplime with a density of 275kg/m3. The wall constructions were initially theoretically analysed using existing approaches and both the stiffness and strength of the wall panels were calculated. Experimental testing was undertaken on 24 full size wall panels. Fifteen were tested with compressive loads, five with in-plane racking loads and four with out-of-plane bending loads. Initially two walls were tested with a concentric compressive load applied to the top of the encapsulated timber studs. The studs were shown to be restrained by the hemp-lime preventing buckling and increasing the failure load by over 500%. Four walls were tested with eccentrically applied compressive loads to investigate bursting of the studs through the hemp-lime surface. On three walls the studs burst through the hemp-lime showing that bursting is dependent upon the hemp-lime cover over the studs. In addition unrestrained studs were tested and shown to buckle at much lower loads than the hemp-lime lime encapsulated studs. Under in-plane racking loads two walls were initially tested and found to have increased stiffness and strength over an unrestrained studwork frame. The leading stud joints were found to be a weak point. These joints were improved and two further walls were tested, one with a sheathing board attached to the studwork frame and one without. The strengthened joints were found to improve the stiffness and strength of the wall panels. The wall panel with sheathing was also found to have a higher stiffness than the unsheathed walls. Two walls were initially tested with applied out-of-plane loads. One wall was hemplime with rendered surfaces and the other included a studwork frame. The studwork frame was found to provide continued load capacity once the render and the hemp-lime had failed. Two further wall panels were tested with a sheathing board attached to the studwork frame and render on the other face of the hemp-lime. Again the studwork frames were found to provide post crack load capacity. The walls were also found to perform with differing stiffness according to the load direction. Following experimental testing the theoretical results were compared with the experimental results. Generally good correlation is seen between the results. Prior to the experimental testing it was not possible to predict the bursting of the hemp-lime when the studs were loaded in compression, however following testing a technique was developed to allow this prediction to be made. In conclusion this study has shown that hemp-lime does enhance the load capacity of studwork framing under both compressive and in-plane racking loads. Under out-ofplane bending loads the studwork frame allows continued load capacity after the hemplime and render have cracked. This study has shown that material savings can be made when using this type of construction as a sheathing board is not necessary as the hemplime can fulfil its structural function. This will contribute towards a more efficient construction system and reduced energy and resource use.

This research uses a novel construction material (lime-pozzolan concrete) and real-world project (a school) as a vehicle for investigating the implementation or applied-innovation process in construction. The implementation of new technologies at a product-level is recognised to be an antecedent of technological change in the construction industry. A ‘real world’ construction project aiming to implement a novel lime-pozzolan concrete in the field, has been used as a process-tracing case study. Rigorous analysis of this case study project, expressly focusing on project-level communication, has shown the implementation of innovative and sustainable materials to be a complex, socio-technical process. With the aim of identifying opportunities to improve project-level design processes in order to support the uptake of innovation and sustainable solutions, twelve high-level theories have been built on twenty-five emergent themes. Collectively these insights demonstrate that implementation processes, once initiated, are experiential, social, contextual, active, interactive, temporal, intentional and mutually constituted phenomena. On the strength of empirical findings this thesis argues for a radical shift in managerial attention from the outcome of the process to the process itself; specifically focused on the experience of the design team as process participants. Laboratory testing and initial field trials have demonstrated the technical feasibility of producing structural grade lime-pozzolan concretes with 28-day compressive strengths of up to 50MPa. The lime-pozzolan concretes were ternary combinations of hydraulic lime (NHL5), ground granulated blastfurnace slag (GGBS) and silica fume (SF). The use of NHL5 in conjunction with pozzolanic materials has been shown to be a viable ‘low-carbon’ alternative to CEMI or CEMIII/A in certain circumstances, although this work has demonstrated that the potential savings in the embodied CO2 and energy of lime-pozzolan concretes are highly dependent on the boundaries of the analysis. Moreover the potential for lime-pozzolan concrete with a lower still CO2 and energy intensity than any concretes tested to date has been identified.