Blog Archives

Paver-Made Streaks

Posted by on 21/ 11/ 15

Let us suppose that an adequately hot mixture is delivered to the job site. Nevertheless, badly adjusted paver elements (in the given examples, badly arranged screed seg­ments) may bring about the formation of porous areas in the course (streaks). Figure 11.13 presents an example of streaks pulled by a paver during laying. Figure 11.14 presents the same effect but photographed with an infrared camera.

11.8.2.1 Paver Standstills

One of the main principles of laying SMA is avoiding a paver standstill. Almost every time the paver is immobile, uncompacted areas behind the machine are the result (Figure 11.15). This effect is heightened if the mixture contains modified binder (higher stiffening of the mixture during cooling down). Figure 11...

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KITCHEN SINKS

Posted by on 21/ 11/ 15

Kitchen sinks require a minimum clear space in front of them that must be 30 inches by 30 inches. This is based on a measurement made from the front face of the kitchen sink, counter, or vanity. Measuring from the finished floor to the top edge of a kitchen sink or counter should result in a measurement of 34 inches, maximum. Unobstructed knee clearance with a minimum of 29 inches high by 8 inches deep should be provided. Toe clearance should be a mini­mum of 9 inches high by 9 inches deep, provided from the sink to the wall.

Additional requirements for a handicap kitchen sink require that all ex­posed hot-water piping be insulated. Faucets should be installed so that they are no more than 25 inches from the front face of the lavatory, counter, or vanity...

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Examples of Test Results

Posted by on 21/ 11/ 15

10.4.1 Laboratory Results

Wetting of unsaturated soil reduces the suction in the soil, the pore pressure ap­proaches the pore air pressure and the effective stress is reduced. Because of this, increasing moisture is associated with decreases in shear strength, stiffness and re­sistance to plastic deformation in all soils and aggregates and we can observe a decrease in bearing capacity and lower moduli of elasticity and increases in de – formability under the same applied loading.

10.4.1.1 CBR Tests

This influence of moisture on the bearing capacity of soils can be easily observed in the simple CBR test. This test measures the resistance of the compacted soil to the penetration of a piston, to evaluate its bearing capacity...

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Multiple-Support Slip Base-Coupler Designs

Posted by on 21/ 11/ 15

Inclined slip base designs, commonly used for single sign supports, cause the sign to rise up upon impact and allow the vehicle to pass beneath the sign. In a multiple-sign- support system, each support is fastened to the other supports by the sign panel and any existing sign panel bracing. When an inclined slip base is used on multiple-support assemblies and only one support is struck, the sign panel stops the impacted support from moving upward. As a result, the slip base can become locked, or the sign panel torn from the other supports, causing intrusion of the panel or support into the vehicle. Inclined slip bases should be used only for multiple-support assemblies when all supports are within 6 ft (1800 mm) of each other. The horizontal slip base (Fig. 7...

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LAVATORIES

Posted by on 21/ 11/ 15

Lavatories installed for handicap use must be of a type that is accessible by a person in a wheelchair (Fig. 10.9). The minimum clear space in front of a lava­tory must be 30 inches by 30 inches. This is based on a measurement made from the front face of the lavatory, counter, or vanity. Measuring from the fin­ished floor to the top edge of a lavatory or counter should result in a meas­urement of 35 inches. How much clearance is required under the lavatory? Unobstructed knee clearance with a minimum of 29 inches high by 8 inches deep should be provided. Toe clearance should be a minimum of 9 inches high by 9 inches deep, provided from the lavatory to the wall.

Additional requirements for a handicap lavatory require that all exposed hot-water piping be insulated...

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Bearing Capacity Measurements In-Situ

Posted by on 21/ 11/ 15

There are many ways of evaluating pavement structural capacity or adequacy and it is very common to perform deflection measurements with non-destructive testing equipment (COST Action 325, 1997). Once again, there is usually no knowledge of the pore pressure or pore suctions in the soil or pavement layer being assessed, so a total stress interpretative framework is necessary even though an effective stress framework would be more desirable.

There are several reasons for deflection measurements to be carried out: for quality assurance, to evaluate the bearing capacity of the unbound material of the granular base, sub-base and subgrade layers, to identify weak parts of the road, to investigate reinforcement requirements, to establish priorities for road strengthening and for research purpose...

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Identification and Estimation of Model Parameters

Posted by on 21/ 11/ 15

A general overview of conventional and some advanced numerical models used in practice has been given in Chapter 9, Section 9.4. Therefore, tests needed for the parameters of these models will now be presented.

• Resilient behaviour models

о Routine pavement design model: in practice much routine pavement design is carried out as catalogue – based design. The pavement is considered as a multi-layered elastic system with constant stiffness parameters in each layer.

о Advanced pavement models: RLT tests are required with variable confining pressure (CEN standard EN 13286-7 (2004)), they correspond to strain sta­bilization...

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Insulating walls and ceilings with fiberglass batts

Posted by on 21/ 11/ 15

The first thing to realize about installing fiber­glass insulation is that you can’t just shove the batts into wall and ceiling cavities any old way and expect them to do their job. Insulation batts must fit snugly between studs or joists and cannot be jammed in tightly or packed loosely and sloppily with gaps all over the place. Kraft paper-faced batts have tabs, which should be stapled to the face of the studs every 12 in. or so.

Many installers staple the tabs to the insides of the studs, which makes it easier to install drywall. However, I don’t recommend this approach. When the paper tabs are sta­pled to the inside of the studs, a slight gap is left along both sides...

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Approved Single Supports for Multiple-Support Assemblies

Posted by on 21/ 11/ 15

There are few single-support systems that can be buried directly and provide accept­able multiple-support performance upon impact. Two such systems are dual 3-lb/ft (4.5-kg/m) U-channel and dual 4-in X 4-in (90-mm X 90-mm) shaped wooden posts. The majority of single-support adaptations to multiple-support assemblies require the use of anchor pieces and breakaway designs. Triple supports consisting of 1.75-in X 1.75-in (45-mm X 45-mm) square perforated tube and triple 2.5-lb/ft (3.7-kg/m) U-channel

NOTE:

RECOMMENDEO TORQUE

ON SUP BASE FLANGED

HEAD BOLT & NUT IS 54 Nm

KEEPER

PLATE

760

kzoo-э!

FIGURE 7.23 Acceptable slip base breakaway device for multiple-square-tube sign assemblies. Dimensions shown as mm. Conversions: 200 mm = 8 in, 760 mm = 30 in,

54 N-m = 40 ft-lb.

are acceptable when i...

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Control or Measurement of Suction/Moisture

Posted by on 21/ 11/ 15

As shown in Chapter 9, Section 9.5, a complete description of a material’s be­haviour necessitates an effective stress approach with the pore pressures (or pore

Number of load pulses Number of load pulses

Fig. 10.3 Typical results from permanent deformation testing where the accumulated axial strain is shown as a function of the number of load pulses in the permanent deformation tests (Erlingsson, 2000) suctions) being separately controlled, or monitored, from the applied pressures. Be­cause most road materials are coarse grained and partially saturated and/or above the ground water table, it usually proves impossible – and certainly it is impractical in most situations – to monitor the pore suctions during each transient pulse...

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