Civil Engineering

Over the last few decades use of fiber to reinforce plain cement concrete (PCC) to improve its ductility, tensile strength and crack and shrinkage resistance has gained a lot of popularity. Bamboo (Bambusa) is a fast-growing grass and abundantly available in India. It possesses sufficient strength, flexibility, toughness and is also very light in weight. Bamboo can be processed to obtain bamboo fibers of required dimensions which could be used as a substitute of steel fibers in order to improve ductility, tensile strength which in turn improves crack and shrinkage resistance of plain cement concrete. Bamboo fibers are also environment friendly and much cheaper than almost all other types of fibers used in concrete construction. Many studies have been carried out on bamboo reinforced concrete (BRC) which mostly deals with bamboo strips as reinforcement in concrete similar to that of steel bars in concrete. However there are very few literatures available on using bamboo in the form of fibers to reinforce concrete. This paper reviews various studies carried out on bamboo as reinforcing material in concrete especially in the form of fibers. Based on previous studies two types of predominantly used bamboo fibers, i.e., i) long slender type and ii) flat chip type, have been identified. The authors intend to conduct experimental investigation using these two types of fibers and comparative analysis also to be made between the test results of concrete specimens reinforced with these two types of fibers to identify its technical viability. Further investigations will be conducted using the type of fiber resulting better concrete properties with various volume content and aspect ratio. In addition, experimental study will also be taken up on concrete specimen partially replacing cement by pozzolanic material and using the same type of fiber.

The Bangladesh National Building Code specifies and regulates the general requirements for structural design and design criteria in Bangladesh (BNBC). In the previous two decades, the introduction of new civil engineering techniques, expertise, and materials has resulted in changes to design parameters and methodologies. As a result, BNBC 2017 was written to reflect the change. To further understand the changes in design and analysis, a systematic parametric structural study of RC frame structures was performed, utilizing both codes via FEA for high seismic and high wind zones (Mymensingh) and low seismic and low wind zones (Chapainawabgang). According to the analysis results, the newer code provisions often result in a less economical design with a greater safety margin when compared to the design-based code provisions. The examination of various analysis and design outputs establishes a well-defined comparison between the two seismic zones. The essential distinction between the two seismic zones based on lateral load (wind and earthquake) is provided. In the case of RCC structures, analysis and design are carried out to demonstrate the change in reinforcement required for different column and beam sections, while the building height remains constant. According to BNBC 2017, this comparison study establishes a clear picture of changes in structural details, cost effectiveness, and safety in between the high seismic and low seismic zones by locating two buildings (Mymensingh and Chapainawabganj).

Water in India is primarily a state subject. Water is the main part of our life. It is a fact that if water is used there will be waste. So the waste water generation will never stop. In construction industry concrete being the most widely construction material used, uses most of the water. In construction industry water is used for mixing, aggregate washing, curing of concrete and for washing concrete related mechanical machines. Also water is used for domestic purposes. So as said above when we use water, waste water is produced. And due to this waste water there is a great environmental impact.The present work deals with the results of experimental investigations on waste water used in concrete. Effect of these different types of waste water on various strengths of concrete are studied. Various strengths considered for investigation are compressive strength, flexural strength, split tensile. Cube of size 150 mm for compressive strength, beams of size 100 mm X 150 mm X 700 mm for flexural strength, Cylinder dia 150 mm and 300 mm length for Split tensile strength were cast. Results were observe and comparison of results of concrete with that of water showed the significant improvements in the results of various strengths like as compressive strength, flexure strength and splitting strength with different types of waste water.

The coastal area of Andhra Pradesh has a hard crust on the top. These top layers of the laterite formations are highly porous but hard and strong. In between this top low level laterites and bottom high level laterites some of the beds are having size distribution between JEDI (clay) and GODI (silt) soils, but do not show the behaviour of the clay nor silt, called shedi soil (lithomargic clay). Shedi soil is the name given to the locally available whitish, pinkish/ yellowish lithomargic soil with high silt content and low bearing strength. When the shedi soil become saturated as a result of rain, it loses its strength and possess the same problems as that of dispersive soil. Usually the low lying areas of Karnataka state are usually filled up with these problematic soils. Construction on these type of soil possess problem of excessive settlement and low bearing capacity.In this paper, an attempt is made to stabilize the shedi soil of Baptla Guntur Dist Andhra Pradesh state using the quarry dust obtained from the Trident infrastructure, Bajpe and lime procured from the local market. The shedi soil was replaced by quarry dust in different proportion of 10, 20, 30, 40 and 50% by dry weight of soil whereas lime was added to soil in proportion of 2.5, 5 and 7.5% by dry weight. A series of laboratory experiments were conducted on the unstabilised bas well as stabilized specimens. All the specimens were prepared at OMC and MDD.

The usage of alternative fine aggregate like silica sand is a natural step in solving a part of depletion of river sand. The research on alternative material for concrete making commenced earlier than half a century. Concrete made from silica sand as fine aggregate was studied for workability, compressive strength. Silica sand is made from crushing of quartz stone. Similarly, observe of its durability will make sure more dependability in its utilization. So here on this assignment, silica sand were used as substitute of fine aggregate for making concrete of M-20, with w/c ratio 0.45. The proportion substitute could be 100% with natural fine aggregates. For making M20 concrete opc-53 grade cement is used. Cubes has been casted and tested compressive strength.

This study presents the structural characterization of sawdust-palm kernel shellcrete composite. It proffers solution to absence of structural characteristics of sawdust-palm kernel shellcrete composite, which is a concrete component mixture of cement, sawdust and palm kernel shell(PKS). The materials used in the experiments work included: Ordinary Portland Cement, saw dust, palm kernel shell and water. The physical characterization tests were performed on the aggregates used in this experimental work, of which sawdust gave values of 554.9kg/m3, 0.503, 33.57%, 2.61, 1.0 and 2.83 for average bulk density, average specific gravity, average water absorption, finess modulus, coefficient of curvature (Cc) and uniformity (Cu) respectively. Palm kernel shell gave corresponding values of 729.09kg/m3, 1.63, 11.8%, 6.03, 1.36 and 2.64. Batching was done by weight and the low bulk density of the aggregate materials (sawdust and palm kernel shell) were taken cognizance of. The mixing of the components were done manually. A total of six (6) cubes of size 150mm x 150mm x 150mm, six(6) cylinders of size 150mm x 300mm and six(6) beams of size 150mm x 150mm x 600mm were produced from mix ratios (water : cement : fine aggregate : coarse aggregate): 0.9 : 1 : 2 : 2 and 0.9 : 1 : 2 : 3 for compressive strength test, split tensile strength test and flexural strength test respectively. The above water-cement ratio and mix ratio was adopted due to the high water absorption of the aggregate materials and to achieve the desired workability, strength and durability for light weight concrete. For the mix ratio of 0.9 : 1 : 2 : 2, the average compressive strength, flexural strength, split tensile strength and average static modulus of elasticity were 7.73MPa, 2.76MPa, 1.57MPa and 4.41GPa. The corresponding values for the mix ratio of 0.9 : 1 : 2 : 3 are 3.84MPa, 2.51MPa, 1.42MPa and 4.06GPa. The average Poisson’s ratio ranges from 0.2 - 0.37. The shear modulus ranged from 1.48MPa – 1.84MPa. The average flexural strength of sawdust-palm kernel shellcrete beams ranged from 2.5MPa to 2.76MPa.

Earthquake damage in most bridges is the result of excessive seismic displacements and large force demands that have been substantially underestimated during design. The detailed study is carried out for continuous box superstructure & substructure for two lane spans 25 m-35 m-25 m, using IRC class A & 70R loadings. For analysis SAP2000 software is used. The results for 12 different cases have been studied and variation of each parameter is documented in a detailed manner. The impact of class of seismic zones corresponding to different soil conditions are studied. The impact of class of seismic zones corresponding to different soil conditions are compared in Spectral Acceleration coefficient Sa/g, Horizontal seismic coefficient Ah, Vertical seismic coefficient Av, Base shear Vb, Displacement at superstructure level. When comparing spectral acceleration, which depends on dynamic property of structure and supporting soil medium, it varies from 1.36 to 1.67 times, when the soil from hard to soft nature. As far as base shear, displacements are concerned, it increases from 1.6 times of hard soil to medium soil, whereas from medium to soft soil it increases to 1.5 times of medium soil.

A study was carried out to evaluate the plant architecture of 27 local cassava cultivars (Manihot esculenta Crantz) in the Bengamisa region. The aim was to find out which cultivars could be used as monocultures or in crop associations for better weed control. We used a randomized complete block design with 27 treatments (27 cultivars) repeated four times. These parameters were measured: height of first branch, number of branches and petiole length after three months' planting. The results obtained showed that the 27 cultivars gave three groups of cultivars in relation to the height of the first branching and the number of branches (early, medium and late cultivars). They also showed that there are early cultivars that can be used in monoculture for better weed control (Apolina, Adjele and Atua); medium cultivars that can be used for both cropping systems (pure or associated) and late cultivars, better indicated for crop association.

The transformation from a conventional consumption based society to a sustainable society is urgently required due to the pollution of the natural environment, the exhaustion of the natural resources and the decreasing capacity of the final waste disposal facilities. One of the ways to solve this problem is to use ceramic waste (CW) concrete as partial replacement with cement in structural concrete. Also to develop a sustainable concrete using new supplementary cementitious material (SCM) like ceramic waste powder which is produced from ceramic tiles at the manufacturing process and dismantled tiles, broken pieces of tiles and it was partially replaced with Ordinary Portland cement (OPC).Concrete mixtures were produced, tested and compared in terms of compressive strength to the conventional concrete. These tests were carried out to evaluate the mechanical properties for 7 and 28 days. As a result, the compressive strength achieved up to 30% replacing cement with ceramic waste. This research work is concerned with the experimental investigation on strength of concrete and optimum percentage of the partial replacement by replacing cement via 0%, 10%, 20%, 30%, 40% and 50% of ceramic waste. Keeping all this view, the aim of the investigation is to study the behavior of concrete while replacing the ceramic waste with different proportions in concrete.

To develop a sustainable concrete using new supplementary cementitious material (SCM) like Lime sludge which is produced in paper industry while producing paper. It was replaced partially with Ordinary Portland cement (OPC). The properties of concrete investigated include compressive strength, split tensile strength, flexural strength and sorptivity keeping optimum percentage of Lime sludge supposedly supplementary cementitious material (SCM). Also compared the cost of sludge based concrete with conventional concrete. In this work, M25 grade was developed and test results indicate that the use of Lime sludge with cement in the concrete has improved the performance of concrete on mechanical properties and cost economical.