Characterization of waterproof-covering mortars on Ottoman monuments of “Ghar El Melh” (Tunisia)

This study is devoted to the characterization of two historic waterproof-coating mortars taken from the ottomans monuments of “Ghar El Melh” in, northeast Tunisia. The first waterproof mortar was recovered from the aqueduct channel, which was used to supply boats with water. The second type came from the terrace cupola of “Sidi Ali El Mekki” fortress. To characterize each mortar, physical, mineralogical, and chemical analyses were performed. These revealed that the two samples were mainly made of air-hardening lime mixed with pozzolanic additions. The binder/aggregate ratio was 0.6 for the aqueduct coating and 0.3 for the cupola. The relative presence of gypsum in the mortar of the aqueduct indicated its sulfatic alteration, but the two coatings were free of ettringite. Although these were in permanent contact with corrosive conditions, the two waterproof coatings showed good durability.     

The physical,chemical,and microscopic properties of masonry mortars from Alhambra Palace (Spain) in reference to their earthquake resistance

Al-Andalus mortar is an ancient binding material (lime mortar) that was used for centuries in numerous historical buildings in Al-Andalus,Granada (Spain).The physico-chemical and microscopic properties of Al-Andalusmortars in Granada were studied as part of an investiga-tion into the mineral raw materials present in the territory of Spain.Scanning electron microscope and X-ray diffraction analyses of eight main types of mortars were performed to show the presence of calcite, gypsum, quartz, and muscovite minerals with organic fibers. Chemical analyses of the specimens showed that high SiO2+Al2O3+Fe2O3 contents yielded high values of hydraulicity and cementation indices. A significant result of this study was that mortars with high hydraulicity and cementation indices have high mechanical strengths.This characteristic may be the main reason for the earthquake resistance of the historical Alhambra Palace.     

Investigation of mechanical and mineralogical properties of mortars subjected to sulfate

The durability can be described as concrete’s resistance to the destructive influences of a medium containing acid, sulfate and/or various chemicals and mechanical effects. The main objective of this study is investigation of mechanical and mineralogical properties of cement mortar with different pozzolanic compositions and subjected to sulfated medium. In the study, the mortars produced with cement samples having seven different compositions and varied with an air-entraining agent were subjected to the influence of sulfate. This study is supported by thin section and X-ray powder diffraction (XRPD) investigations, in addition to being subjected to the basic tests, such as compression and flexure. The most important findings obtained from the study are that the compact structure has more effective properties against sulfate effects for cement mortars than pozzolanic materials’ effects and the highest pozzolanic material ratio is restricted about 25–30% by mass because this ratio is a boundary of mechanical properties.     

Relationships between geotechnical properties of the Antalya travertine (Turkey)

The Plio-Quaternary travertines are exposed in the vast area around the Antalya region. Travertine is the major subgrade formation in this area. For geological and geotechnical purposes the Antalya travertine can be divided into three different groups and these are spongy, weak, and massive travertine. Geomorphogically the travertine is dissected into four major plateau, namely Dösemealti, Varsak, Düden, and Arapsuyu. The study is specially based on the geological and geotechnical properties of the Lara travertine included in the Düden plateau. The upper most spongy travertines locally can be mixed with underlying weak travertines. The massive travertines are dominantly micritic and brownish and beige in colour. The weak travertine comprises block, gravel, sand, and silt-grade materials coming from massive travertines. Rock Quality Disignation for spongy is “poor”, weak and massive is “fair”. Unit weight in order is 13.2, 15.6 and 19.9 kN/m³. Mean porosity is between 52.47% and 25.23% and all of the travertines are “extremely porous”. Mean permeability in order is 78.4, 42.2, and 8.2 litre/minute. Schmidt hardness of spongy is “very soft”, weak is “soft”, and massive is “moderate”. The uniaxial test results range between 2.37 and 19.0 MPA. The massive travertine is classified as “middle modulus ratio” and “very low strength”.     

Determination of bioclimatic comfort in three different land uses in the city of Erzurum,Turkey

This study was carried out to determine the human bioclimatic conditions in rural, urban and urban forest areas in the conditions of the city of Erzurum, where an extreme continental climate type prevails. Data were obtained over a 10-month period and human bioclimatic conditions in these three different land-use types were evaluated using human bioclimatic indices, suitable for the data obtained. In the study, thermohygrometric index (THI), which assesses air temperature and relative humidity, and “beer garden days” index, which uses the days when temperature at 21:00 is over 20 °C, were used. While in these three areas “hot” and “comfort” ranges were determined to be 10% of the period, the number of “beer garden” days was only 20 days in rural, 15 days in urban forest and 18 days in urban areas of Erzurum. Consequently, it has been determined that the most suitable area for the human comfort in the conditions of Erzurum is in the urban area which is followed by the urban forest and the rural areas, both for each observation time and across the whole period.     

Physical and mechanical properties of mortars without cement

In this study, production of mortars with disposable polyethylene bottles, but without cement, was investigated. The disposable polyethylene bottles were crushed and converted into fiber formation. Then fibers were molten with different types of sands at the temperature range of 180-200 °C. Some physical (e.g. water absorption and abrasion resistance) and some mechanical (e.g. bending strength, compressive strength, toughness) properties of mortars were tested. The results indicated that bending strength and toughness of mortars were improved. Besides, water absorption of mortar was negligible and abrasion was nearly equal to zero.     

Thermal conductivity of limestone from Gaziantep (Turkey)

In this study, thermal conductivity (TC) of limestone from Gaziantep, Turkey, was investigated. The limestone samples were collected from different parts of the city representing Gaziantep and F?rat formation which are clay and chalky limestone. TC of the samples was measured for saturated, partially saturated and dried conditions. Water absorption, dry unit weight and apparent porosity of the samples were also measured to correlate with TC. Measurements showed that TC was increased with increasing the water content of samples. The TC of the samples decreased while the porosity increased. Relationships between TC and both dry unit weight and porosity were driven. There was a very good exponential relationship between TC and saturation degrees of sample, porosity and density. Moisture content increased TC up to 113%.     

A proposed weathering classification for basalts and their engineering properties (Turkey)

Most of the volcanic rocks widespread in Turkey are basalt. The effect of weathering processes on the physical and mechanical properties of this type of rock is important. To assess these properties and relations to each other, a study was undertaken in the Niksar region. A detailed investigation was carried out on basalts in the road cuttings of the Niksar ring road and Ünye-Akku?-Niksar highway alignments. A new classification system for basaltic rocks which are substantially influenced by weathering is proposed. The basic engineering properties of the basalt representing each weathering grade were determined. The properties tested are dry density, porosity, coefficient of permeability, uniaxial compressive strength, tensile strength and Young’s modulus. Interrelationships were determined for all test results. It is concluded that there is a substantial degradation in the engineering properties of the rock beyond a specific degree of weathering.     

Geo-engineering properties and settlement of peaty soils at an industrial site (Turkey)

Peats consist of the partly decomposed remains of vegetation, which have accumulated in waterlogged areas. They are often unsuitable for supporting structures of any kind due to their high water content, high compressibility, low shear strength and high degree of spatial variability. The paper reports a preliminary study on peats from industrial sites in the city of Kayseri, Turkey. The soils in the study area are classified as peat to muck. The peats are fibrous at shallow depth and become amorphous as they extend to some 8 m depth. The ranges of geo-engineering properties are generally consistent with those reported in the literature, with some variation due to their higher mineral soil contents. The behavior of the peats is essentially frictional, with high friction and relatively small cohesion. The direct shear tests yielded higher shear strengths than those from the triaxial tests, due to the fact that the peat specimens used in the direct shear tests were rich in fibers and mineral soils. Back analysis of the settlement of heavy rolls of metal wires laid on the peat generally confirmed the consolidation properties of the soil determined in laboratory.     

Influence of weathering on the engineering properties of Harsit granitic rocks (NE Turkey)

Weathering and hydrothermal alteration of the granitic rocks in the Eastern Black Sea Region (NE Turkey) are important phenomena affecting the engineering projects in the region. The study investigated the probable paths of rock-forming mineral transformations due to weathering in the Harsit granitoid rocks, the changes of the major oxides as a consequence of weathering and the effects of weathering on the engineering properties. To identify the changes in the major oxides, the volume concentrations were considered in relation to the dry density. Chemical leaching during weathering was shown to be significant in changing the minerals. It was concluded that the engineering properties of the weathered granitic rocks can be most reliably predicted by P-wave velocity.      

Microstructure and properties of cement mortars containing organo-modified reservoir sludge

Reservoir sludge can be organo-modified by a cation-exchange reaction and then employed as a substitute for a portion of fine aggregates in cement mortars. The chemical structure and properties of organo-modified reservoir sludge (OMRS) were first analyzed by conducting a series of TGA, FTIR, EDS and XRD measurements. The microstructures of cement mortars containing different amounts of OMRS particles were then characterized by using MIP, EDS and a water contact angle goniometer. In addition, the effects of OMRS particles on the compressive strength and permeability of cement mortars were evaluated. Experimental results indicate that the hydrophobic OMRS particles randomly distributed in cement mortars contribute to the decrease in capillary porosity and the increase in water diffusion barriers. As a result, an adequate dosage of OMRS particles to give a higher compressive strength and a lower permeability ratio for cement mortars is proposed here.     

纳米SiO2对水泥饰面砂浆性能的影响

研究了纳米SiO2改性水泥饰面砂浆的性能,同时利用环境扫描电镜对砂浆的微观结构进行分析.结果表明,纳米SiO2掺量为1.5%～2.5%时,砂浆的抗压、抗折强度和拉伸粘结强度最大增幅均超过60%;纳米SiO2掺量为0.5%～1.5%时,毛细孔吸水率可降低约40%;纳米SiO2掺量为1.0%～3.0%时,抗泛碱性明显改善;纳米SiO2掺量为0.5%～3.0%时,砂浆耐沾污性优于基准砂浆.纳米SiO2能细化砂浆的孔结构和水化产物Ca(OH)2晶体尺寸,使砂浆更致密.     

复掺激发剂对无水泥砂浆性能的影响

为了改善无水泥砂浆水化过程中的碱性环境,进一步提高砂浆的力学性能,试验通过控制激发剂总量,并改变激发剂组合中各组分的掺量比例来研究其对无水泥砂浆性能的影响,试验结果表明:完全采用粉煤灰、高炉矿渣及生石灰作为胶凝材料的无水泥砂浆的表观密度值均大于OPC;不同龄期未掺入激发剂的N0S0K0组强度值均明显低于OPC,而N7.5S0K0,N5S0K2.5及N2.5S0K5三种组合的无水泥砂浆强度值均与OPC相当,甚至高于OPC。     

General material properties of Denizli (SW Turkey) travertines as a building stone

The quality and material properties of Denizli travertine as a natural building stone have been investigated. The Denizli region is one of the world’s major travertine deposits and production basins. Travertine blocks are extracted from over fifty quarries in the region. In this study, investigations and evaluations of experimental test results of travertine samples from six areas (Kakl?k–Kocaba?, Honaz–Emirazizli, A?a??da?dere, Akköy, Karaçay and Çivril), which represent the entire Denizli basin, are presented. Kakl?k–Kocaba? is the biggest production area in the region, and therefore most of the quarries are located in this area. Physical, mechanical, micro-structural and macro-structural properties of the travertine samples are evaluated within the scope of stone quality assessment. Variations of test results by area are presented, and correlations between them are proposed. Test results are also compared with the results of various studies from Turkey and other parts of the world.     

The accelerating effects of the microorganisms on biodeterioration of stone monuments under air pollution and continental-cold climatic conditions in Erzurum, Turkey

The aim of this research was to determine the accelerating effects of microorganisms on the biodeterioration of stone under air pollution and continental-cold climatic region in Erzurum, Turkey. Studies have been carried out on specimens of the Rustempasa Bazaar, the Lalapasa Mosque, the Erzurum Castle Mosque, the Double Minarets-Madrasah, the Great Mosque and the Haji Mehmet Fountain aged from 441 to 823 years old. The results showed that vegetative and reproductive (generative) forms of the microorganisms could develop during the winter months when the night time average temperature was even -25 degrees C. Also the reproductive forms had developed and the whole stone surface was covered with a biofilm caused by the microorganisms. Silicon, aluminum, calcium, potassium, titanium, magnesium, zinc, sulfur, iron, sodium, and niobium were found in the stones of the historical buildings with varying amounts through the SEM-EDS analysis. Some of these elements could be used as an energy resource for the microorganisms together with the air pollutants such as sulfur dioxide, nitrogen oxides and particles on the stone surfaces. Of 21 isolates, 15 species from 6 bacterium genera and 5 species from 5 fungi genera plus 1 fungi genera were identified on the deteriorated stone surfaces even during the coldest months by microbial identification system (MIS) and these findings were tested by SEM investigations.     

新型环氧树脂乳液改性水泥砂浆性能的研究

研究了环氧树脂乳液对水泥砂浆力学性能的影响，耐酸碱性的影响。采用电子扫描显微镜（SEM）分析了环氧胶乳网络结构与水泥砂浆的作用机理，以及环氧树脂乳液水泥砂浆微观结构形态。     

Delayed ettringite formation (DEF) in mortars of white cement

In this study white cement CEM I-52.5 and white limestone cement CEM II-LL, A and B, with 15% and 25% limestone substitution, were studied. The way delayed ettringite forms, due to exposure to high temperatures (50 °C) and external sulphate attacks, was examined in the mortar samples.The mortars were immersed at 50 °C for 180 days in: (a) a saturated Ca(OH)₂ solution and (b) a 5% Na₂SO₄ solution. During the experiment’s duration, the mortar samples were being observed visually on a regular basis while their expansion was estimated on a weekly basis by measuring the change of length with a micrometer. At the end of the experiment, the mortar samples’ compressive strength was determined and the deterioration products were identified through means of X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM-EDAX), Thermogravimetry (TG) and Infra-Red Spectroscopy (FT-IR).Concluding it is evident that the amount of ettringite is proportional to the C₃A content of cement. Sulphates amount in cement is the controlling factor for heat induced ettringite formation since when they are consumed the reaction stops. On the other hand in the case of external sulphate attack another important controlling factor is the compressive strength of the cement; the higher compressive strength the lower the risk of expansion. Finally, in the case of external sulphate attack, limestone, when added to cement, was proved to enhance the durability against sulphates attack when compared to a cement of the same class.     

激发剂种类及掺量对无水泥砂浆性能的影响

为了优化工业垃圾粉煤灰、高炉矿渣及生石灰作为胶凝材料的无水泥砂浆配合比设计,提高无水泥砂浆的基础性能,试验通过改变碱性激发剂的种类及掺量,研究了无水泥砂浆的表观密度及力学性能,得出了一些有价值的结论。