Masonry Magazine January 1972 Page. 22
THE HIGH
BOND CLASSROOM
a monthly feature by Amspec
The development of the mortar mix used with SARABOND® brand mortar additive was no accident. Years of research have gone into designing an easy-to-follow mixing procedure which incorporates strength and workability to the highest degree. Any mortar, whether conventional or high bond, must contain three basic materials: sand, cement and water. Cement and water, of course, make up what is referred to as the paste portion of the mortar. This paste is what hardens, sticks, bonds and holds the mortar together. This mixture of cement and water does not perform well by itself. The cement-water mixture will shrink and crack as it dries if ample sand is not present. The sand also supplies bulk and volume to the mortar at a very low cost. But here is where the tricky balance comes.
Each sand particle has a unique shape which allows it to stick close to other sand particles. The void area between sand particles is called void volume. (Sand and void volumes will be discussed more fully in future articles.) The void volume of the sand determines how much cement or other filler material is needed to fill all the voids between sand particles, and still allow enough excess cement to bond to the brick and strengthen the mortar.
Unless the void volume is filled with cement paste, the mortar is usually lean or sandy. When too much cement and filler are added and the void volume is overfilled, you will have a fat or rich mortar. This balance must be easy to attain.
The mortar proportions used with SARABOND are designed to make this balance easy. SARABOND is packaged in 4-gallon containers, which is the exact amount used with a full 94-1b. bag of portland cement. Sand is measured in a cubic foot box to avoid shovel-ful inconsistencies.
A 50-lb. bag of ground limestone is used as the work-ability additive in place of lime. Ground limestone is the ingredient which adds plasticity to the mortar. An approved ground limestone helps fill in the voids in the sand and produces that nice fatty texture. In a future article we'll show you why ground limestone is used instead of lime.
Use of these premeasured quantities will help eliminate potential mixing problems. Proper proportions and mixing procedures will provide the best workability and the greatest yield.
The sand and water are the variable materials which allow you to adjust your mortar mix to give you the best combination of aggregate and cementitious materials. After two batches, you will know how much sand gives you the best mix and produces the desired workability.
Really, each batch of high bond mortar will be the same day after day because the only variable left is the water. And one to two gallons of water... potable water. will usually be enough.
Washington Wire
maintained because that's where they wield the most influence. Congressional committee chairmen do not like the plan either. Reason: some related committees would be abolished.
Nixon will make a campaign issue out of reorganization-claiming the Democrats don't favor government efficiency.
A FAMILY HEALTH PLAN FOR MAJOR ILLNESS may well be approved in 1972. But it is unlikely that the bill offered by the Administration will carry. Critics say it is tailored to the insurance industry rather than consumers. A compromise between Democratic-backed bills and the Nixon measure is seen.
Subsidizing private plans is the key to the Nixon plan. The Democrats want the Federal government to foot the entire bill.
PENSION REFORM LEGISLATION APPEARS TO BE A SURE BET for this year. The long-awaited Administration measure was sent to Congress late in 1971. Minimum standards will be established for the vesting of pension benefits for preserving the pension rights even of employees who leave their jobs. Generous tax breaks will be offered to the self-employed who set up plans. Contributions up to $7,500, or 15% of annual income, would be deductible. Benefits may also be offered to employees who wish to save for retirement.
IMPORTANT LABOR LEGISLATION WILL BE ENACTED by Congress this year. A higher minimum wage will be pressed by the Democrats as a campaign issue. The Democrats and labor want a $2 an hour floor put into effect this year. The President is ready to support a rise to $1.80, with $2 an hour in 1974. The Democratic-controlled Congress may push through the more generous plan.
Stronger enforcement of job discrimination laws may be voted. The Equal Employment Opportunity Commission will get new policing powers. The House voted last year to give EEOC the power to seek court injunctions. But the Senate will no doubt authorize cease-and-desist powers a stronger remedy.
SOME CONSUMER PROTECTION MEASURES WILL FINALLY WIN approval in 1972. Federal government standards for product warranties will be voted this year. The Senate passed legislation requiring guarantees to be clearly detailed; little opposition is likely when the measure reaches the House for a vote. The Federal Trade Commission may well receive new weapons for enforcement. A bill would provide for stiff fines for engaging in deceptive practices. FTC could also seek restraining orders or injunctions to halt such conduct. And it could go to court for redress for the victims of unfair practices.
New action to protect the public from hazardous items is on the way. The goal is to reduce or eliminate unreasonable risks of death or injury. There is some disagreement between the President and Congress on details of the bill. But a compromise is likely to be worked out before the year ends.
WATER POLLUTION CONTROL WILL BE MIXED WITH POLITICS on Capitol Hill. The Administration is trying to soften a tough pollution control measure.