Test 3 CIM 310

Advantage of Central Mix Plant

Higher Production Rates

Plant operator responsible for:

Loading mixer and controlling discharge

4 element of wet plant operation

Charging Time, Mixing Time, Discharge Time, Return Time

Typical Mixing time for 10 yd3

2 min

plant equipment which gives it ability to blend ingendients before entry into mixer

efficient mixing

Fluid and consistent mixes provide

faster discharge

Central Batch Plants are capable to

start next batch while discharging

Slump affects amperage needeed to mix, higher amperage means

stiffer concrete

types of mixers

horizontal and tilt up

standand equipment, most part and pieces can be maintained by plant operators

In-house maintenance

maintenence for Batching Control Panel, electrical equipment

Specialized maintenence

tool to keep track of several activities in the daily operation and control of the batch plant.

daily plant log

Basis of strength in concrete

W/C ratio

Admixtures for concrete are

Chemical and Mineral

Concrete achieves ___% of untilate compressive strength in 7 days

65-75

what percentage does the paste represent in the concrete mixture

20-40

A mixture in a freshly harded state, delivered to the site is

Ready Mix Concrete

High Profile Bacthes have components:

above ground level

Whats is the difference between wet-batch plants and dry-batch plants

The Mixer

Liquid advixture dosage is in:

floz/yd3

minimum concrete temprature of concrete mixtures in cold weather is:

50F

Batch plant mixers can be grouped in:

Tilt and horizontal mixers

non-agitating trucks are used for:

short haul projects

10yd3 concrete buckets are helpful for:

high elevation

concrete mictures made a mobil truck mixer is commonly:

Volume based

Common concrete barrel size in NJ is:

4-12 yd3

production, delivery and placecmnt of ready mix concrete is based on:

ASTM C-94

Scale that has a counter weight

Scale Lever

Scale that is electronic

Single Load

Scale that has no moving parts

Four Point

In batching, Cement should be weighed:

First

In batching Pozzolans should be batched:

Second

water batching can be done by:

Volume and Weight

loading method which blends fine and coarse and cememt before

Ribbon Batching

Loading method where trucks get aggregate, water and admixtures; thenthey move to the next station to get the cement

Dry Batching

How many types of batch plants are usually considered

Wet and Dry

Performance and Prescription basis are _____ and ____ to order conrete

options and criteria

easiest way to increase temp of concrete is

heating water

concrete batch plant is the equipment where ________ is manufactured

ready mix concrete

configuration of batch plant based on

Location of components and high or low

W/c ratio, unit wieght, slump are

characteristics of concrete mixture

formula for absolute volume of material

weight of material/(spec grav x density of water)

tail water is ___%

15-30

What has a greatest impact on batching process

Aggregate moisture

Tolenances and calibration governed by

Concrete Plant Manufactures Bureau

Which condition is more expensive to solve in batching

Overweight

Checking weather forecast and air compressors are part of activities included in the ____

activities, daily checklist

aeration of cement silos when air pressure is applied at ___ psi

0.5-5

Typical batching tolerances for cement, aggregate, water, admixtures

0.3 of scale capacity, 1211 required weight

Bulk density varies from ________ lbs/ft3depending on degree of aeration

60-94

What 2 conditions slow down the batching-discharge process and increase the potential errors and batch accuracy?

Vacuum and Pressure

How much water is allowed to continue into mixing time

up to 25%

factors affecting truck ability to accept material

mixer design, drum opening size, rotational speed, slump

types of aggregate moisture

Free, SSD, Absorbed