The precipitation system CIPS (Calcite In-situ Precipitation System) has been created as a permeation grouting system based on a two component fluid with the intention of slowly permeate and fill the pores. It causes cementation through a chemical reaction which bonds the soil particles together at the contact points. CIPS mimics one of the natural reactions in nature where sandstone is formed through calcite precipitation. This system is used in Australia with excellent results and there are many factors governing the outcome of the method, some of these factors are: flow rate, pressure, time, chemical recipe, temperature, composition of the soil matrix and number of performed injections at the same point of location. Some of these factors have been the focus of this report and where they have been examined from a Scandinavian point of view where our ground temperature conditions and soil compositions have governed the outcome of the accomplished results. The strength increase has been examined through laboratory tests where natural sand from a building site with known particle size and dry density has been treated once with the CIPS Fluid. This treatment was completed in a temperature controlled room of 12 degrees after which the treated soil was tested by unconfined compression tests. Even a rather low increase in bearing capacity of the soil would result in benefits during the construction of temporary constructions during the early building stages foundation work. Since the desired increase in bearing capacity of the soil is fairly low, 50-100 kPa, the investigations has concentrated on one single injection, in order to study if there is a clear trend in the increase in bearing capacity, and if it can be roughly predicted. In addition to the above mentioned laboratory work a small scale field test has been conducted, where the CIPS Fluid was injected into the ground with the aim of creating a column shaped object. This column was left for a certain time, a time long enough for the calcite crystal to bond the soil grains and generate an increase in strength. When the assumed cementation had occurred an ocular assessment was carried out in order to predict whether the strength had increased or not, and to what degree. Based on the laboratory results, some evidence of that strength increase occurs due to either the discharge of the spent fluid containing ammonium chloride or the process of drying. Either way, the strength increase takes place during the grounds natural process of adjusting towards the natural water content equilibrium for the specific site of interest. A strength increase at the laboratory experiments of between approximately 60-220 kPa has been achieved. The field tests where slightly less rewarding when difficulties of injecting the CIPS Fluid into the sandy soil arose due to challenging task of designing a pumping system where both a low pressure, less than the overburden pressure, and a low flow rate, less than 7 litres per minute, could be controlled. The flow rate could be controlled but with the effect of the pressure rising to too high levels. Due to the observations of CIPS Fluids exiting the ground at other points than near the injection spear, soil fractures are assumed to have occurred at one ore many locations. The volumes treated with CIPS Fluid displayed no increase in strength as long as they appeared somewhat wet with the spent fluid. When this fluid containing ammonium chloride vanished from the treated soil and the pH-value dropped, the build up in strength through calcite crystallisation at the contact points began. This crystallization which leads to a cementation was observed at the centre of the small spheres achieved through injection in the ground, which proves that the Calcite In-situ Precipitation System has caused a cementation of the soil grains treated.

O crescente interesse na utilização de biomateriais para reparação óssea levou a inúmeros estudos envolvendo formação de diversos produtos, neste sentido, os compósitos obtidos utilizando-se gelatina (G), quitosana (QS) e hidroxiapatita (HA) destacam-se por serem bioativos e bioabsorvíveis, além de apresentarem elevada similaridade com o tecido a ser reparado. Barreiras físicas formadas por tais materiais são extremamente importantes para a odontologia, e o seguinte trabalho tem como objetivo a preparação de membranas de G/QS/HA a partir de um método de co-precipitação in situ da HA na matriz polimérica para sua utilização em regeneração tecidual guiada (RTG). As membranas contendo razões de 20/80, 50/50 e 80/20 de G/QS com 0,3M de HA foram preparadas com pequena adição de glicerina (0,5% v/v) e suas características morfológicas e físico-químicas foram analisadas por meio de técnicas como espectroscopia no infravermelho (IV), difração de raios X (DRX), microscopia eletrônica de varredura (MEV), espectroscopia por energia dispersiva (EDS) e análise termogravimétrica (ATG). Além disso, foram realizados ensaios de intumescimento e ensaios de citotoxicidade in vitro com cultura de células para verificar a possibilidade de utilização das membranas confeccionadas. O processo de precipitação in situ foi eficaz para formação das mambranas. Além disso, as amostras reticuladas por GTA apresentaram melhores resultados de intumescimento, ao passo que as membranas reticuladas por TPP não se mostraram citotóxicas. / The increasing growth in the usage of bio-composites in bone repair has led to several studies involving the formation of several products. In this sense, composites obtained with gelatin (G), chitosan (QS) and hydroxyapatite (HA) stand out since they are bioactive and biodegradable, besides showing high similarity with the tissue to be repaired. Physical barriers made by such materials are extremely important in orthopedics, and the present work aims to craft G/QS/HA membranes by an in situ co-precipitation method of HA in the polymeric matrix to use them with a treatment called guided bone regeneration (RTG). The membranes containing 20/80, 50/50 and 80/20 weigh percent of G/QS with 0,3M of HA were prepared with a small amount of glycerin (0,5% v/v) and its morphological and physicochemical properties were analyzed by infrared spectroscopy (IV), X-ray diffraction (DRX), scanning electron microscopy (MEV), electron energy loss spectroscopy (EDS) and thermo gravimetric analysis (ATG). On top of that, swelling essays and in vitro cytotoxicity with cell culture were be carried out to check the availability and possible uses of the crafted membranes. The in situ precipitation method was effective to form the membranes. The samples crosslinked with GTA showed better swelling results, however the TPP method yielded non-cytotoxic membranes.

O crescente interesse na utilização de biomateriais para reparação óssea levou a inúmeros estudos envolvendo formação de diversos produtos, neste sentido, os compósitos obtidos utilizando-se gelatina (G), quitosana (QS) e hidroxiapatita (HA) destacam-se por serem bioativos e bioabsorvíveis, além de apresentarem elevada similaridade com o tecido a ser reparado. Barreiras físicas formadas por tais materiais são extremamente importantes para a odontologia, e o seguinte trabalho tem como objetivo a preparação de membranas de G/QS/HA a partir de um método de co-precipitação in situ da HA na matriz polimérica para sua utilização em regeneração tecidual guiada (RTG). As membranas contendo razões de 20/80, 50/50 e 80/20 de G/QS com 0,3M de HA foram preparadas com pequena adição de glicerina (0,5% v/v) e suas características morfológicas e físico-químicas foram analisadas por meio de técnicas como espectroscopia no infravermelho (IV), difração de raios X (DRX), microscopia eletrônica de varredura (MEV), espectroscopia por energia dispersiva (EDS) e análise termogravimétrica (ATG). Além disso, foram realizados ensaios de intumescimento e ensaios de citotoxicidade in vitro com cultura de células para verificar a possibilidade de utilização das membranas confeccionadas. O processo de precipitação in situ foi eficaz para formação das mambranas. Além disso, as amostras reticuladas por GTA apresentaram melhores resultados de intumescimento, ao passo que as membranas reticuladas por TPP não se mostraram citotóxicas. / The increasing growth in the usage of bio-composites in bone repair has led to several studies involving the formation of several products. In this sense, composites obtained with gelatin (G), chitosan (QS) and hydroxyapatite (HA) stand out since they are bioactive and biodegradable, besides showing high similarity with the tissue to be repaired. Physical barriers made by such materials are extremely important in orthopedics, and the present work aims to craft G/QS/HA membranes by an in situ co-precipitation method of HA in the polymeric matrix to use them with a treatment called guided bone regeneration (RTG). The membranes containing 20/80, 50/50 and 80/20 weigh percent of G/QS with 0,3M of HA were prepared with a small amount of glycerin (0,5% v/v) and its morphological and physicochemical properties were analyzed by infrared spectroscopy (IV), X-ray diffraction (DRX), scanning electron microscopy (MEV), electron energy loss spectroscopy (EDS) and thermo gravimetric analysis (ATG). On top of that, swelling essays and in vitro cytotoxicity with cell culture were be carried out to check the availability and possible uses of the crafted membranes. The in situ precipitation method was effective to form the membranes. The samples crosslinked with GTA showed better swelling results, however the TPP method yielded non-cytotoxic membranes.