Given below is the graph which shows the relationship between water/cement ratio and compressive strength of concrete. It can be observed from the image that the relationship is hyperbolic in nature. Figure 1: Relation between strength and water/cement ratio of concrete The compaction of concrete is the process adopted for expelling the entrapped air from the concrete (Shetty 2010). Higher the amount of air entrapped, lower is the workability of the concrete. Even wet cement i.e. concrete with high water/cement ratio is not favourable because it can cause voids when the water dries from the pores. Compaction thus becomes essential in the process of preparation of concrete. 100 percent compaction is necessary to ensure zero percent voids. There are chiefly four methods of compaction and they are as follows: Hand Compaction – Rodding, Tamping, Ramming etc. Compaction by Vibration – Internal, External, Table Vibrator, Platform Vibrator, Surface Vibrator, Vibratory Roller etc. Compaction by Pressure and Jolting Compaction by Spinning In our experiment, we have adopted hand compaction and compaction by vibration using vibration table. We performed hand compaction by tamping it with a tamping rod and packing the constituents tightly in the mould. Compaction by vibration is the most efficient method of compaction and gives best results for low water/cement ratio concrete. Where only a concrete of a desired strength is required, it can be obtained by compaction by vibration of leaner mixes than possible with hand compaction, thus making the process economical. The demerit of hand compaction of concrete is that it can only be done in unimportant concreting works. It cannot be used for compaction of high-quality concreting. Also, hand compaction is subjective to the individual performing it and the compactive effort may vary from person to person. The demerit of compaction by vibration table method is that it can be used only for small prefabricated RCC members. From figure 1, we can find that high water/cement ratio is required when concrete is hand compacted as compared to the case when the concrete is vibrated. It can also be seen from the graph that when the water/cement ratio is below the practical limit, the compressive strength decreases sharply. The compressive strength is calculated by dividing the load at failure with the surface area of the cube. EQUIPMENT The various equipments and materials that were required in the experiment have been listed as following: 20 moulds of 100mm 2 tamping rods 1 vibration table 1 mixer 1 wheelbarrow 1 measuring cylinder Trowel Metal scoops Compression Testing Machine MATERIALS Cement CEM1 Water Sand Coarse Aggregate PROCEDURE 1. We will take the quantity of cement, sand and aggregate in the following proportions: Cement CEM1 1.70 kg Sand 3.40 kg Coarse aggregate 5.10 kg (natural coarse aggregate) 2. We will add the contents in the mixer and then add the required water by calculating it from the water/cement ratio. 3. We will take out the concrete and put it into the 4 moulds. 4. In 2 out of the 4 moulds, the compaction will be done by vibration through the vibration table while in the other 2 moulds by hand. 5. The moulds are left for curing for 14 days. 6. The cubes are then tested for compressive strength in the compression testing machine. 7. The reading of the load at which the cube fails is noted down and plotted
TABLE OF CONTENTS S.no. Content Page 1 TABLE OF CONTENTS 1 2 OBJECTIVE 2 3 THEORY 2 4 EQUIPMENT 4 5 MATERIALS 4 6 PROCEDURE 5 7 RESULTS 8 8 ANALYSIS/DISCUSSION 14 9 CONCLUSION 15 10 REFERENCES 16 LAB 3: Water/Cement Ratio (W/C) OBJECTIVE The objective of this experiment is to obtain the relationship between the compressive strength of concrete, water/cement ratio and method of compactness…
Concrete, can be defined as a composite material used in construction composed mainly of aggregate, water, and cement. It has several formulations, which give properties that tend to vary. This aggregate consists crushed rocks or coarse gravel like granite or limestone this is mixed with other fine aggregate like sand.
This practical utilized the plasmid vector pUC19, a common vector used for cloning small DNA fragments in Escherichia coli. pUC19 is 2686bp in total size and contain an origin of replication that enables the given vector to replicate in E.coli. pUC19 replicates in E.coli to produce approximately 100 copies per cell.
Basil plants were planted in three samples of soils that comprised of typical potting, sand, and black soil. Their heights were measured after every seven days for a period of two weeks. The results of the experiment partially supported the hypothesis. The speed growth of basil plants in typical potting was attributed to environment.
The material grades are specified as SPCC and SPCG steels. SPCC is a commercial quality cold reduced carbon steel sheets and strips whereas SPCG steel is an extra deep drawing quality non-aging steel. Both types of steels are cold rolled carbon dead mild steels.
Moreover, it is necessary to evaluate the performance of the business organization for measuring the fundamental financial status and implications as a whole. While evaluating the annual financial situation of General Motors, it is crucial to maintain the disclosure of the income statement, balance sheet and other relevant accounting frameworks.
Also included was a question of perceptions of the ideal form of the opposite sex. Gender differences were found overall in that women and men had different patterns of responses. All hypothesis were supported, women rated their ideal lower than their actual, men were similar in their ratings of both, women rated their ideal as lower than what men considered the ideal female form, and men rated their ideal as higher than what women considered the ideal male form.
What was the latency of the response
Answer: The data from sheet 1 showed the elbow flexion unloading response of the biceps. The weight was removed unexpectedly as we can see the unloading reflex in the bicep provoked by the load release. The latency time is about 55 milliseconds.
Immunoglobulin G (Ig G) is the most common antibody type used in immunocytochemistry. The variable region (Fab portion) of the antibody binds it to the epitope part of the antigen. In this practical, the tissue sections were blocked and