EXPERIMENT marshall stability and flow test for bitumen

Introduction

The Marshall stability and flow test provides the performance prediction measure for the Marshall mix design method. The stability portion of the test measures the maximum load supported by the test specimen at a loading rate of 50.8 mm/minute. Load is applied to the specimen till failure, and the maximum load is designated as stability. During the loading, an attached dial gauge measures the specimen's plastic flow (deformation) due to the loading. The flow value is recorded in 0.25 mm (0.01 inch) increments at the same time when the maximum load is recorded. The important steps are as follows;

Step 1; sample is weigh as following table;

Table 1.0; Mix ratio

Material	%	gm
20 mm aggregate	38	427.56
10mm aggregate	8	90.00
Q. Dust	52	585.00
Cement	2	22.50
Total	100 %	1125.00

g 1.0; Aggregate samples

Step 2; The sample is kept in oven to dry, till the sample reaches 150 deg C.

Fig 1.1; Dry oven

Step 3; to make the temperature rise faster, the sample was placed in fry pan and mixed well, and frequently check the temperature of the sample if it has reached 150 deg C.

Step 4; Bitumen sample is weight as following (table 2) and the aggregate and cement from the table 1 in the fry pan are been mixed .

Table 2; bitumen weight

1	4.5 %	53.00 gm
2	5.0 %	59.20 gm
3	5.5 %	65.50 gm
4	`6.0 %	71.80 gm
5	6.5 %	78.20 gm

Fig 1.2; Bitumen and aggregate sample been mixed in fry pan

Step 5; the 1^st sample is poured in to the mould after mixing it in the fry pan, and the sample is left for its temperature inside the mould has reached 130 deg C.

Step 6; When the temperature has reached 130 deg C, the sample is placed in the Marshal compactor, Marshal Compactor gives an impact load x75 times and this is done on the both sides (top and bottom).

Fig 1.3; Marshall Compactor

Step 7; Compaction process is completed, the sample is removed from the mould, and label the sample, so that it won’t be confuse with other samples.

The above steps are repeated for all the samples, after that measure the thickness of each sample, if any sample is less than 60mm consider it as failure, recode all the reading in lab table (Marshall Test results). Measure the weight of each sample in Air, Water and saturated. Before Marshall test, the sample must be place in water bath for 45 min to 1 hour at a temperature of 160 deg C.

Fig 1.4; Marshal property curve

Table 3

Marshall properties	% Bitumen contant optim curve	Critenia	Space limit
Stability	5.0	1.384	> 750 Kg
Flow	5.2	3.6	>2.0 mm
Density	5.5	2.365	-
UFB	5.2	8.0	75 % - 85 %
VIM	5.0	4.0	3% - 5%
Optimum B/contant	5.18	-	-

Experiment on Hydrostatic Pressure

Theory of experiment

The hydrostatic force on any surface is due to the fluid pressure acting on that surface. Pressure is a normal stress which is positive when in compression. Since the pressure is everywhere normal to the surface, the resultant pressure force (F_p) is also normal to the surface. The magnitude of F_p is

where p = gysin a, g = specific weight of the fluid, y = distance measured from level of zero pressure and measured in the plane of the surface, and a = angle which the plane of the surface makes with the horizontal.

Partial Immersion :

Objective of experiment

To determine the center of pressure on a partially submerged plane surface.

Apparatus

Hydraulics Bench F1-10 and Hydraulics Pressure Apparatus F1-12.

Procedure

1. The quadrant has placed on the two dowel pins and used the clamping screw, fasten

to the balance arm.

2. Measured a, L, depth d and width b of the quadrant end face.

3. The balance arm have positioned on the knife edges (pivot) with the Perspex tank on

the bench.

4. The balance pan have hanged from the end of the balance arm.

5. A length of hose is connected from the drain cock to the sump and a length from the

bench feed to the triangular aperture on the top of the Perspex tank.

6. The tank has leveled by used the adjustable feet and spirit level.

7. The counter balance weight is moved until the balance arm is horizontal.

8. Closed the drain cock and admitted water until the level reaches the bottom edge of

the quadrant. Placed a weight on the balance pan, slowly adding water into the tank

until the balance arm is horizontal.

9. The water level on the quadrant and the weight on the balance pan have recorded.

10.Fine adjustment of the water level can be achieved by overfilling and slowly draining

by used the stop cock.

11.The above for each increment of weight has repeated until the water level reaches the

top of the quadrant end face.

12.Removed each increment of weight noting weights and water levels until weights have

been removed.

Results and calculations

FILLING TANK		DRAINING TANK		AVERAGE
Weight, m(g)	Height of water, y(mm)	Weight, m(g)	Height of water, y(mm)	m	y	y2	m/y2
50 70 90 115 150	42.5 51 58.5 66.5 77.5	50 70 90 115 150	42.5 51 58.5 66.5 77.5	50 70 90 115 150	42.5 51 58.5 66.5 77.5	1806.25 2601 3422.25 4422.25 6006.25	0.028 0.027 0.026 0.026 0.025

The measurement for the equipment ;

a = 26.5 mm, b = 74 mm, d = 167 mm, L = 275 mm

Plot m/y² vs y graph. The slope of this graph should be – pb/6L and the intercept should be pb/2L (a+d) . The – pb/6L and pb/2L (a+d) is theory part.

Experiment Part

Let a₁ = slope of the graph let b₁ = intercept for the graph

= - 0.0015/20 = 0.039 g/mm²

= - 7.5 x 10^-5 g/mm³

Theory Part

Since the theory and experiment result are different, it should to find out the percentage different between them by using following formulas :

Discussion of results

From the results obtained, the slope for the graph is -7.5 x 10^-5 g/mm³ and the intercept is 0.039g/mm². However for the theoretical result for the slope is -4.485 x 10^-5g/mm³ and the intercept is 0.026 g/mm². For the normal situation, the slope and the intercept for experiment part should be same with the theoretical part. If even there are different, but if the different percentage is not more than 10 %, the results still can be accepted.

For this experiment, after obtained the different percentage between the theoretical part and experiment part, is found that the different for the slope between both side is 67.22% and the different for the intercept between both side are 50%. So that the different between both site is more than 10 %, this lab results not acceptable.

There are so much differences between theoretical and experimental part caused by human error. This can be occurred because when taking the reading, it only use eyes look at the reading directly and not by some apparatus which is more accuracy. This laboratory results out of the range from normal situation also caused by mistake when filling water and draining water from the tank.

Conclusion

From the experiment done, it is a way to determine centre of pressure. This laboratory is considered not well but laboratory test sometimes will not success. It may caused by many reasons.

How to Make ground water well

what is a ground water well, thats the a very traditional method used to in collecting water where the other sources of water or rivers are far away, if u wanna know a lot more about more technical detail and kids of wells used for ground water.

firstly you'll need is good form-work to preppier the cylinder part of it, so what was used is a steel framing with 1.2meter (4 feet) in diameter and 1.2m (4FT) in height as in the pic shown, this type of shuttering or form work has two parts init, external shuttering and internal shuttering. all the steel shuttering is bolted together with 9mmx 25mm bolts at each connection, always we have to prepare the internal shuttering first.

after u have carefully prepared the internal shuttering its time to start with the steel work, steel used for vertical is 10mm deformed bar at 150mm spacing, and horizontal as rings its 6mm round bar at spacing of 150mm. since the wall thickness of this well is 120mm, make sure to add a wooden block in between the shuttering before u completely bolts it.

once the steel bars are been handled, insert the cover blocks so that the steel bars wont be touching the form work, what have been used for cover blocks is 35mm small blocks around 2inch by 2 inch, if u wanna knw how to make simple concrete cover blocks visit bigatoll.come, well any how making a cover block is pretty simple.

after u have completed the steel work, concrete cover blocks its time for you to place the external covering for the form work. if you wanna find out how much of concrete needed for 1m³ of concrete visit yd-mv.com this website has a free concrete calculator. now start mixing the concrete in the ratio of 1:2:3. make sure its a bit wet like 60% water, this will help you to get rid if the honey combing that will occur, but dont forget to use a mechanical vibrator, good vibration has to be done after each load of concrete has been poured into this shuttering.

once the concrete has been poured, give the form work 24 hours to dry out, than carefully remove the bolts and remove the shuttering, Always remove internal form work first than external form work, this is because the concrete haven't got its full strength and giving 1 day means its surface is dry. so there will be cracks if u try removing the external first. so keep in mind internal than external. leave the concrete for curing with wool bags till 7 days, so it will reach the peak of strength starts to gain. spray water 2 times a day so that it will keep wet and no thermal crackings occurs.

while the 7 day period is there, use that time to cast a new concrete cylinder part for your well, if you have heavy machinery than it will be a advantage for you, but if u dont u have to wait till the 7 day period is over than to put the form work on top of it to precast a new concrete.

if you have an excavator, excavate the place where you want to keep the well, mark the location of the well, than dig the place till water or more than water, in this case water depth was something like 1.2 meters, since Maldives is a flat land water table is petty high and the island is 1meter above sea level.

when the excavation is done, place the pre caste concrete in side the hole, use a crane or a the excavator, while lifting heavy objects you must be very careful, cos every where there are nut cases running around.

excavating ground water well

Source: Courtesy of YD Works

once the well is placed, start another concrete on top of this well with connection the rods or place another concrete cylinder on top of it. once the pieces is placed, start manual excavation from inside of the well, the more soil u remove underneath the concrete, it will slowly starts to sink down, ground water well are sinks like this and its called the sinking method.

in this case YD Works used a mini dredger pump of 4", this pump can suck water with soil, this way some soil underneath the concrete wells will come plus there will be one labor always digging the soil and sand out of it. once the sinking starts try not to stop digging till your done, while your digging the soil around the external surface is been pulled down to your shovel, there will be a gap forming between the external surface and the ground, once that gap is started to from that means its ready to sink, if u get stuck sprey some water to the bottom that way soil erosion will occur giving you more sand to pull up.

top concrete cover plate been laid

Source: Courtesy of YD Works

pre cast concrete cover is 150mm thick and steel of 10mm deformed bar been placed at 150mm spacing both ways, there is an opening of 2ft by 2 ft, a concrete cover has to be made so that no one falls in it, this cover is cast with 6mm steel bar with 80mm spacing T/B.

there you go, now thats a short way on how to build ground water well, now please visit bigatoll.com and find out more other stuff. we would like to thank YD Works for providing us with the pics and detail info on how the work has to be done, bigatoll.com send regards and thanks to YD Works.

Bitumen test for Viscosity

Viscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. In everyday terms (and for fluids only), viscosity is "thickness" or "internal friction". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity. Put simply, the less viscous the fluid is, the greater its ease of movement (fluidity).

The viscosity test measures the viscosity of an asphalt. Both the viscosity test and the penetration test measure the consistency of an asphalt at some specified temperatures and are used to designate grades of asphalts. The advantage of using the viscosity test as compared with the penetration test is that the viscosity test measures a fundamental physical property rather than an empirical value. Viscosity is defined as the ratio between the applied shear stress and induced shear rate of a fluid.

When shear rate is expressed in units of 1/sec. and shear stress in units of Pascal, viscosity will be in units of Pascal-seconds. One Pascal-second is equal to 10 Poises. The lower the viscosity of an asphalt, the faster the asphalt will flow under the same stress. For a Newtonian fluid, the relationship between shear stress and shear rate is linear, and thus the viscosity is constant at different shear rates or shear stress. However, for a non-Newtonian fluid, the relationship between shear stress and shear rate is not linear, and thus the apparent viscosity will change as the shear rate or shear stress changes.

Asphalts tend to behave as slightly non-Newtonian fluids, especially at lower temperatures. When different methods are used to measure the viscosity of an asphalt, the test results might be significantly different, since the different methods might be measuring the viscosity at different shear rates. It is thus very important to indicate the test method used when viscosity results are presented.

The most commonly used viscosity test on asphalt cements is the Absolute Viscosity Test by Vacuum Capillary Viscometer (ASTM D2171).

The standard test temperature is 60 °C. The absolute viscosity test measures the viscosity in units of Poise. The viscosity at 60 °C represents the viscosity of the asphalt at the maximum temperature a pavement is likely to experience in most parts of the U.S. When the viscosity of an asphalt at a higher temperature (such as 135 °C) is to be determined, the most commonly-used test is the Kinematic Viscosity Test (ASTM D2170), which measures the kinematic viscosity in units of Stokes or centi-Stokes.

Kinematic viscosity is defined as: When viscosity is in units of Poise and density in units of g/cm, 3 the kinematic viscosity will be in units of Stokes. To convert from kinematic viscosity (in units of Stokes) to absolute viscosity (in units of Poises), one simply multiplies the number of Stokes by the density in units of g/cm3.