Terrestrial Laser Scanner as a Tool for Assessment of Saturation and Moisture Movement in Building Materials

Non Destructive Testing (NDT) is a key element of modern civil engineering. It is especially important in civil and structural engineering helping both in quality control of produced elements and technical assessments of existing structures. Existing NDT methods are being continuously improved and new methods are developed or adopted from different engineering fields. Terrestrial Laser Scanner (TLS) method which is commonly used for geodetic applications has a great potential to be successfully harnessed in civil and structural engineering. TLS can be used for remote sensing of saturation of building materials. A research programme was prepared in order to prove this concept. Specimens representing most popular European building materials were scanned using TLS. Tested specimens were in different saturation states including capillary rising saturation. The saturation assessment was based on differences of values of intensity. The concept proved to be feasible and technically realistic

Lightweight SFRC benefitting from a pre-soaking and internal curing process

The presented research program is focused on the design of a structural lightweight fiber-reinforced concrete harnessing an internal curing process. Pre-soaked waste red ceramic fine aggregate and pre-soaked artificial clay expanded coarse aggregate were utilized for the creation of the mix. Copper-coated steel fiber was added to the mix by volume in amounts of 0.0%, 0.5%, 1.0%, and 1.5%. Test specimens in forms of cubes, cylinders, and beams were tested to specify the concrete characteristics. Such properties as consistency, compressive strength, splitting tensile strength, static and dynamic modulus of elasticity, flexural characteristics, and shear strength were of special interest. The achieved concrete can be classified as LC12/13. A strength class, according to fib Model Code, was also assigned to the concretes in question. The proposed method of preparation of concrete mix using only pre-soaked aggregate (with no extra water) proved to be feasible.Web of Science1224art. no. 415

Fresh Mix Characteristics of Self- Compacting Concrete Reinforced by Fibre

An analysis of influence of different types of fibre and fibrecontent on properties of self-compacting concrete is the mainsubject of the paper. Presented study is focused on the effect ofsteel, basalt and polypropylene fibres with different geometricalparameters on workability and self-compacting abilities offresh mixes

Steel Fibers and Steel Fiber Reinforced Concrete in Civil Engineering

ABSTRACT Since the beginning of applications of civil engineering materials based on clay, lime, and cement, there has been a need to find a way to decrease their brittleness. In ancient times, the problem was solved by modifying brittle clay bricks with the addition of fibers of an organic origin. These approaches can be examined through a reading of the descriptions of Roman baths construction (Vitruvius 1999). Today it is steel fiber which is mainly used to reinforce concrete and overcome the problem of brittleness. This paper describes the most interesting applications of steel fiber reinforced concretes (SFRC) all over the world. Firstly, the author presents the evolution of steel fibers and SFRC. Secondly, the paper covers the contemporary importance of SFRC in civil engineering

Application of TLS intensity data for detection of brick walls defects

Terrestrial Laser Scanning (TLS) is a well-established technique for remote acquisition of geometrical data of a tested object. For the past two decades it has been commonly used in geodesy, surveying and related areas for acquiring data about spacing of civil engineering structures and buildings. An average TLS apparatus, apart from 3D coordinates registers radiometric information of laser beam reflectance. This radiometric information of the laser beam reflectance is usually called intensity and has no meaning for solely geometric measurements. Nevertheless, the value of intensity depends mainly on physicochemical properties of scanned material such as roughness, colour and saturation. Keeping these facts in mind, authors suggest using changes in value of intensity to locate various imperfections on a brick wall. So far, authors have conducted a thorough and successful research programme dedicated to detection of saturation and saturation movement in brick walls. Based on this experience a new research programme was conducted focused on various aspects of detection of brick wall defects. The main aim of the paper is to present the possibility of using the intensity value in for the diagnostics of the technical condition of a brick walls. Advantages and limitations of harnessing TLS for detection of surface defects of brick walls are presented and discussed in the paper.Peer ReviewedPostprint (published version

Change of Fatigue and Mechanical Fracture Properties of a Cement Composite due to Partial Replacement of Aggregate by Red Ceramic Waste

Fine-grained cement-based composites used in civil engineering and construction industry are usually made of cement-based matrix and natural aggregate (such as sand, gravel, crushed stone, etc.). Red ceramic waste aggregate is considered as a perspective replacement of a part of natural aggregate in modern environmentally oriented building materials. Fine-grained cement composite with natural aggregate partially replaced by ceramic waste aggregate usually show different mechanical fracture characteristics from ordinary fine-grained concrete. The specimens were tested at six different ages. This was the reason for conducting the research programme. Altogether, 6 fine-grained cement mixtures with various proportions of natural and red ceramic waste aggregate were prepared. The aim of this paper is to present and compare mechanical fracture properties obtained from static and fatigue tests. Bulk density, flexural and compressive cube strength, fracture toughness and fatigue properties (S−N − Wöhler curve) were of special interest. All of these tests are important for a practical application of concrete with ceramic aggregate for structures. All the results were statistically analysed and they showed that the fatigue and mechanical fracture properties were improved or at least kept up with the increasing levels of red ceramic waste aggregate. Environmental impact of application in construction industry of composites in question is discussed

Mechanical fracture properties of concrete with lunar aggregate simulant

From the volumetric point of view, aggregate is the most important ingredient in any kind of concrete. It is impossible to use raw soil instead of aggregate to produce concrete. There are numerous reasons for not using soil for concrete production on Earth, and we should not use lunar soil for concrete production on the Moon for the same reasons. Nevertheless, almost all developed lunar concrete-like composites, such as sulphur or polymeric concretes, are based on raw lunar soil. In the research programme, cement composite based on lunar aggregate simulant was tested. The mechanical fracture properties of the composite were the key point of interest. It was proven that the tested lunar concrete is characterized by stable and uniform properties. The obtained results were compared with the properties of other ordinary cement composites

Strength and Durability Characteristics of Cement-lime Mortars with Fly Ash and Slag as Aggregate Substitutes

The global consumption of sand by the concrete industry has increased significantly over the years. Natural sand has become a desired commodity in numerous regions of the world. To protect both the existing resources of natural sand and utilize waste materials, drastic actions are urgently needed. The production of cement mortars, which are solely based on fine aggregate, is responsible for the large consumption of natural sand. In the described research program, we proposed to substitute 50 % of the natural sand in mortars with fly ash and slag. The strength properties and durability characteristics of the new mortars were tested. It was proved that mortars with fly ash and slag can be used for specific applications in civil engineering. Areas for future research associated with the mortars in question were also pointed out

Influence of Varied Waste Ceramic Fillers on the Resistance of Concrete to Freeze–Thaw Cycles

Our research focused on the influence of fillers obtained from crushed waste materials on the selected properties of concrete composites. The used waste materials were sourced from the production of ceramic tiles, ceramic pots, and sanitary ceramics. We evaluated concretes modified with the addition of 10% (by mass of cement) of different fillers. The properties, including the air content in the fresh concrete mix, consistency, compressive strength, and freeze-thaw resistance were examined. The evaluation of the freeze-thaw resistance was carried out by testing the concrete with the direct method for 150 cycles of freezing and thawing. The characteristics of the concrete porosity structure were assessed using automated digital image analysis. Concretes modified by coarse and fine fillers were characterized by different improvements in the mechanical properties and resistance to cycles of freezing and thawing. Composites with the addition of coarse fillers did not show any significant changes in comparison to the control concrete. An automated digital image analysis of the pore distribution in concrete proved to be an effective tool for the assessment of the freeze–thaw resistance of the concretes in question

Impact Resistance of Sustainable SFRCC Road Pavement

The examinations of properties of steel fiber reinforced cement composite (SFRCC) specimens do not reflect properties of these composites in an actual pavement, tunnel or bridge. Each, even the most basic road pavement or structure, works within constantly changing conditions, where different loads appear and disappear in time. The impact strength of SFRCC is strongly influenced by a number of factors that tend to increase the statistical variations. Therefore the design of SFRCC elements should be based on statistical considerations of their properties. A drop weight test is the simplest test for evaluating impact resistance as the relative performance of plain cement composite and SFRCC containing different types and volume fractions of fibers. The research program was divided into three main stages. The first stage covered VeBe test, measurement of density of hardened composite and compressive strength. The main aim of the first stage of this research program was to check quality and homogeneity of the cement composites. The second stage covered multiple drop-weight load. During the drop weight procedure, the ultrasound test was conducted after each five impacts. The third stage covered statistical analysis of achieved results. The carried out experiments have shown that the ultrasound method combined with statistical methods are well used to monitor changes of mechanical properties of SFRCC used for road pavements or structure during dynamic destruction process. Time needed for the ultrasound wave to pass through a composite was main information about process of destruction occurring during an impact test (internal cracks in the composite structure make the way that ultrasound wave propagates longer comparing to undamaged structure of the composite). The results of the ultrasound propagation time measurements were analyzed based on a statistical approach