vertical joint (figure 15c, d). With the increase of horizontal load to a growing area of cracking, bed joints and cracks also appear in the bricks. At the time of the destruction cracking covered almost all the head joint. As in the case of walls with steel bars, in places where the truss type reinforcement was located cracking intensity was less than the near the face of wall. Initial deformation of the truss bars, like the smooth bars were tensile and uniform– figure 16a.
One way to prove that the items mentioned above are causing the difference between the proposed force-displacement analysis results and the force-displacement envelopes obtained during testing is to subject the wall system to another analysis where the bar forces are known, and the force from the actuator is solved for. In other words, using static equilibrium at the limit state values (at the end of the first cycle in the push direction at prescribed levels), with the forces from the post-tensioning taken from the load cell readings, the force in the actuator can be solved for (for free body diagram, see Figure 13.9) by summing moments around the centroid of the masonry compression
The current construction technique requires that the standard, rectangular confinement plate be threaded over the top of reinforcing steel and placed in its corresponding position between the transverse steel as depicted in figure 4.3. This current procedure can be quite awkward and time consuming, potentially increasing the construction cost of masonry structural walls. Therefore a different confinement plate configuration was implemented in specimen 4 to ease construction. The plate, referred to as the “Durham Plate”, shown in figure 4.4. has an open end, which allows for simple placement of the confinement plate in the desired location without any significant conflicts with any steel reinforcing bars. The plate style needed to be evaluated before implementation due to well established torsional theory, which states a closed section provides a significant increase in torsional rigidity than an open section. Therefore the
Aggregates are considered as one of the main constituents of concrete since they occupy more than 70% of the concrete matrix. In many countries there is scarcity of natural aggregates that are suitable for construction whereas in other countries the consumption of aggregates has been increased, in recent years, due to increase demand by the construction industry. In order to reduce dependence on natural aggregate as the main source of aggregates in concrete, artificially manufactured aggregates and artificial aggregates from construction wastes provide an alternative for the construction industry. Therefore the utilization of aggregates from the construction wastes can be alternative to the natural and artificial aggregates. Crushed masonry wall is derived from the construction waste. Due to the process of demolish or unanticipated conditions (earthquake) the huge quantity of brickmasonrywalls are available. This masonry wall is involved in crushing process then the crushed powder of the wall is obtained. We use this powder is the alternative material for the fine
The basic requirements for human survival are food, cloth and shelter and housing is one of those basic requirements. Brickmasonrywalls are used for the construction of all types of building in many parts of India and elsewhere because of the lower price, locally available raw materials, good strength, easy construction with less supervision, good sound, and thermal insulation properties, availability of skilled labor etc. Brickmasonry is a composite material in which brick units are systematically arranged with the help of mortar joints. In India, various types of bricks or blocks are used as a masonry unit. They are clay brick, fly ash brick, solid concrete block, hollow concrete block, F-LAG Brick (Fly ash, lime, and Gypsum brick), CLC Block (Cellular Light Weight Concrete Block), AAC Block (Autoclaved Aerated Concrete Block) etc as shown in Figure-1. Now a days clay bricks and fly ash bricks are using in building the structure as a general practice. Also, several mortars are used in joints of two building blocks. They are strong in compression but weak in tension. Hence the cracks are easily propagated on the surface of the masonry structure due to having low ductility. Before using them as a building material, they must be satisfied the minimum strength. The different types of strength of clay brickmasonry analyzed by various researchers are discussed here.
In the micro modeling approach, all constituent material of the concrete block and solid brickmasonrywalls as distinct mechanical properties are independently described. Distinct materials are used to represent the behavior of concrete part, masonry units, vertical and horizontal joints and the potential cracks in the middle of the units. The mechanical properties used in the description of the material models are obtained from an experimental test carried out on materials and masonry assemblage [8, 14, 15]. A three-dimensional cohesive interface model is used for modeling of interfaces in this paper. This model is based on smooth yield surface reduces the computation time and restricts the failure of corners [16, 17]. Also, LS-DYNA has fully automated contact analysis capability, which makes this software very user-friendly for contact analysis problems . All mechanical parameters used for numerical modeling are shown in Tables 2-5. According to Lorenco, it is useful to model potential cracks in units in order to avoid over-estimation of the collapse load and stiffness. Therefore, potential cracks are placed at the middle length of units and modeled with interface elements by discrete cracking model, Tables 3 and 4 . The constitutive law for discrete cracking by LS-DYNA is based on total deformation theories which express the stresses as a function of the total relative displacement [18-20]. Normal and shear stiffness of potential cracks are considered as K n =10 6 N/mm 3
Two girders were placed side by side such that their flanges would act as the base for the walls. These girders were place on the bottom member of the loading frame. A layer of mortar was placed on the girders to provide a uniform and levelled base for the wall. The walls were built on this levelled surface as per IS code recommendations with 1 cm thick mortar. A layer of mortar was also provided at the top so that load would be transmitted uniformly. A total of eight walls were constructed comprising of four hollow concrete block masonrywalls and four brickmasonrywalls. Fig.2 shows brick wall constructed on a loading frame.
Minarets are tall and slender structures and they are vulnerable to seismic loading. In the Turkish style, the parts of a minaret are the footing as a base; pulpit, transition segment, cylindrical or polygonal body as a shaft; balcony; upper part of minaret body; spire and flag. There was at least one minaret in each village in the affected area. Many of the minarets were constructed using masonry materials like stone and baked clay brick. Several minarets were damaged during the earthquakes, especially its flag and spire as shown in Fig. 20.
Capacity analysis uses the original design forces as seismic demands and realistic capacity (not limited by code design capacity) and ductility calculations as the median capacity. The primary load carrying system of the structure has to be identified. Then the critical structural components of the system have to be examined (walls, slabs, columns, masonry block walls, foundations, etc.). Finally, the expected median capacities and associated variability of the various types of the load-carrying elements are calculated.
Masonry is the oldest building material that is still used in the building industry. The placing of brick units on top of each other bonded with mortar has revealed itself as a successful technique during thousands of years, which is mainly justified by its simplicity and the durability of the constructions. In-spite of the simplicity associated with the building in masonry, the mechanical behaviour of masonry construction remains a true challenge. The basic mechanical properties of the masonry are strongly influenced by the mechanical properties of its constituents namely brick and mortar. Masonry buildings have proved to be most vulnerable to earthquake forces and have suffered maximum damages in the past earthquakes. Hence, buildings in earthquake-prone regions require adequate seismic shear strength along with their vertical load carrying capacity. The use of masonry as a composite material has been favored in the construction of buildings and civil infrastructures as it is simple and sophisticated with durability, aesthetic appeal and economic advantages. However, the inherent weakness of masonry in tension has been repeatedly demonstrated in seismic events. The need to overcome seismic deficiency of unreinforced masonry panels has led to the development of structural walls with reinforcement. when exposed to harsh field conditions.
This was a study on the behavior of a confined masonry bearing wall in a medium height dual building. This wall had to be placed at one corner of the building. It had to be a masonry wall, not to be too stiff and drag the rigidity center too far from the building’s center. The structure’s stiffness was also to be analyzed by using a concrete wall instead of the masonry one, as an alternative solution. This showed the importance of using a masonry wall. The dual structure contained only one other wall, made of reinforced concrete. The 2 bearing walls bore most of the shear force from seismic loads, because they were the stiffest load bearing elements in the structure. It was interesting to see if the masonry wall could bear these loads. The structure was unusual, as it contained frames, a concrete and a masonry wall. These elements behave differently. The structure was analyzed for both the elastic and plastic stage. The loadbearing elements stiffness, the stresses development and structure failure mechanism were studied for both solutions. The results showed it is appropriate to use a masonry wall at the corner. This wall can bear the loads it is subjected to.
Masoney infills works as compressive strut, infills have more significant in lateral loads such as seismic and wind forces as compared to vertical loads. The masonrywalls used for partition purpose in buildings will contribute to initial lateral stiffness significantly. In severe earthquake loading the walls will get cracked and contribution to lateral stiffness is negligible. Masonrywalls can be modeled as diagonal strut model or continuum plate model. The foregoing considerations will often mitigate against the use of isolated panels, and the subsequent discussion will be limited to interacting structural infill, where the role of the infill in influencing stiffness and strength is fully considered in the design process. In this work, STADD Pro software has been used in order to analyze and design RCC frame structure (G+6)
The empirical verification of strut-and-tie models on wall models with cantilevers or partially fixed, performed in foreign research centres, produced successfully converge results. However, using the model with discrete or smeared struts, or partially cracked residual model not always produced results convergent with the test results. The reason was the complex strength parameters of masonry and working conditions of walls. On the other hand, the national tests provided less optimistic results for fixed walls. Moreover, they indicated the impact of slenderness as the results obtained from the models with discrete and smeared struts were clearly different from the case of slender walls. Some corrections to mechanical parameters were made to provide the satisfactory convergence between observations and calculations for squat walls. To sum it up, the present state of knowledge, particularly with reference to empirical verification, is not sufficient to unequivocally define rules applicable to individual models. Using the mixed type III model, composed of both discrete and smeared struts, seems to be the most reasonable. However, further analyses experimental verification of different types of walls are required to detail the rules of model building and estimate the potential unreliability of the obtained results. References
Professor and Head, Department of Civil Engineering, Coimbatore Institute of Engineering and Technology, Coimbatore Assistant Professor, Department of Civil Engineering, Coimbatore Institute of Engineering and Technology, Coimbatore _____________________________________________________________________________________________________ Abstract - Brick is one of the widely used materials for the construction of walls in building. In many cases the walls built are get failed due to excess lateral loads. Generally bricks cannot withstand to a large amount of lateral loads. Ferrocement casing given to the brick wall gives an additional strength to wall and ferrocement casing is the use of the wire mesh on the wall and dry mortar is sprayed in it. The main advantage if ferrocement is in which it can be moulded into any shape. Different types of steel wire mesh are taken and casing is done in ferrocement masonry column and the strongest column with higher strength is calculated. The column with use of 0.354mm mesh has higher resistance to lateral load.
Brick wall construction is commonly used for low-cost dwellings in developing nations. This system, being extremely brittle, performs poorly during earthquakes. The Reinforcement embedded brickmasonry demonstrates the practically and economy of construction, and their performance confirms the soundness of the design principles. Reinforcement embedded bricks in brickmasonry consists of brickmasonry which incorporates steel reinforcement horizontally embedded in bricks through mortar. This masonry has greatly increased resistance to forces that produce shear and compressive stresses. The reinforcement provides additional tensile strength allowing better use of brick masonry’s inherent compressive strength. The two materials complement each other, resulting in an excellent structural material.
brick is called "sleep brick", and the vertical brick is called "standing brick". There are three kinds of masonry methods about Cavity Wall: one sleep one standing, one sleep three standing and all standing no sleep (Fig.1).Although there is a pattern masonry method, but specific to each one dwelling the wall, its masonry law is not unified. Usually less than one meter in Cavity Wall used the more sleep brickmasonry method such as one sleep one standing, one sleep three standing and so on. Higher than one meter in Cavity Wall used the more standing brickmasonry method, even the all standing brickmasonry method. It will not only save material, the structure is also reflected by the light weight, high stability characteristics. There is also some Cavity Wall is filled with yellow mud in its empty bucket, which have better thermal performance compared to Cavity Wall just only filled with air in its empty bucket. Therefore, the study will be conducted in accordance with each masonry method for filling different Cavity Wall.
groove wide enough for a 0.079 inch (2.0 mm) thick strip of FRP and 0.039 inch (1 mm) of epoxy on each side of the FRP. A vice was made to hold the brick prism in place as the skill saw cut through the specimen. The vice made of 2” x 4” (50.8 x 101.6 mm) pieces of lumber was placed on concrete slabs that were in the yard of the CFL. For the stacked bond specimens, the groove would be placed in the center of the brick prism. For each prism, the centerline was marked based on that particular brick prism’s dimensions as seen in Figure 3-5. For the running bond prisms, the groove was also cut approximately down the center of the prism but occasionally this line had to be adjusted to avoid cutting through the vertical mortar joint that ran parallel to the groove. The brick dust seen in Figure 3-6 was created from cutting into the brick prisms was collected and saved for later use. Upon completion of cutting into the bricks, the prisms were brought inside and an air hose was used to push air through the grooves to remove any remaining brick dust.
Yield line theory is an analytical approach based on the principle of virtual work, idealized crack (or yield) lines and rigid body behavior. Yield line theory is especially useful in cases were two-way action develops and simple ultimate flexural strength equations do not apply. One disadvantage to this approach is that for FRP-reinforced walls, the determination of the bending moment per unit length of the crack line is not straightforward. Korany & Drysdale (2007) used this approach to predict the post-cracking response of wall panels undergoing two-way bending. Experimental results showed that the crack patterns of the FRP-reinforced walls were quite similar to those of the corresponding unreinforced walls and therefore the idealized crack patterns of the FRP-reinforced walls were represented by the crack patterns of the counterpart unreinforced walls. The post-cracking response was analyzed using rigid body principles in which the displacement is governed by rotation rather than curvature as in the case of bending theory. The failure criteria were defined by a limiting rotation corresponding to masonry compression failure found through the experimental investigation. Comparisons between experimental and analytical results showed good agreement for the ultimate load, overestimation of the ultimate displacement, and good agreement of the energy absorption and deformability. Similarly, Gilstrap & Dolan (1998) used yield line theory to predict failure moments, though no details of this analysis were provided.
An experiment investigation is carried out to study the effect of brick powder and lime on engineering and strength properties of the black cotton soils. The properties of stabilized soil such as atterberg limits, compaction characteristics and California bearing ratio and their variations with content of brick powder and lime were evaluated. Laboratory studies to investigate the possibility of utilizing brick powder and lime as stabilizing materials to improve the engineering properties of black cotton soil was carried out. Black cotton soil is classified as A-7-5 in accordance with HRB soil classification system. The results obtained show that the moisture density relationship follows a trend of decreasing optimum moisture content (OMC) and increasing maximum dry density (MDD) is the modified proctor test. The CBR value of BC soil obtained was only 1% and this low strength value is improved to minimum requirement of 8% CBR according to IRC: 37-2012. Test results indicate that CBR value of soil increases with increase in BP and lime content. Addition of optimum percentage of brick powder (50%) and optimum percentage of lime (4%) and optimum percentage of its combination (30%+1.5%) to the Black Cotton Soil has improved the strength characteristics BC soil 8% CBR. Thus, the significant increase in CBR value of soil stabilized with BP, lime and BP + Lime will substantially reduce the thickness of the pavement subgrade.
This study highlights the behavior of confined masonrywalls in a medium height dual building. The walls will be used to limit the building drifts. This is an office building, 3 stories high, which will be built in Bucharest Romania. This is considered a high seismic area, the seismic acceleration is 0.30g (g is the gravity acceleration). According to the architecture demands, the building’s partitioning needs to be flexible. This is why walls will be placed on the perimeter of the building and not inside it. Walls assure lower drift values. Both masonry and reinforced concrete walls may be used in this example because this is a medium height building. However, masonry is susceptible to cracking. Dynamic loads may cause irregular deformations . Load-bearing masonrywalls show a complex behavior due to the load eccentricity. Walls slenderness reduces the bearing capacity . Studies on masonrywalls have shown that shear force capacity is reduced with the increase of bending moment . Masonrywalls reinforcements help the masonry to work together with the confining elements  and an increased number of confining columns improves the walls strength, the energy dissipation capacity, the ductility and the cracking pattern . According to the model experiments, the confined masonry and concentrated reinforced masonry structures have been used for low and medium-rise buildings in seismic areas . Seismic actions cause