Where New Engineers Deliver New Ideas!

1. Where New Engineers Deliver New Ideas! Spring 2007

2. Specifications • “Specifications” is a general term applying to all directions, provisions, and requirements pertaining to the performance of the work and payment for the work. (Much of this presentation comes from the State of Colorado,Design Guide 2005,http://www.dot.state.co.us/DesignSupport/Design%20Guide%2005/)

3. Construction Documents • Drawings • Provide project requirements best described graphically • Specifications • Provide project requirements best described verbally. • Where there is a conflict between the drawings and the specifications, the specifications take precedence.

4. What Specs Do • “Well-written specifications are essential to the efficient construction of a successful project. Well-written specifications inform the Contractor of the work to be performed, the conditions and restrictions on performance of the work, the expected quality of the work, and the manner in which the work will be measured for payment.” (from CDOT) • “Work requirements must be clearly stated in the specifications.” (from CDOT)

5. Well Written Specifications • are clear, concise, and technically correct. • do not use ambiguous words that could lead to misinterpretation. • are written using simple words in short, easy to understand sentences. • use technically correct terms, not slang or “field” words. • avoid conflicting requirements. • do not repeat requirements stated elsewhere in the Contract. • do not explain or provide reasons for a requirement. • state construction requirements sequentially. • avoid the use of awkward phrases such as “and/or” and “him/her.” Rewriting the sentence can eliminate such phrases. [Personal and relative pronouns cause confusion.] (from CDOT)

6. More Requirements • Make sure that grammar and punctuation are correct. • Avoid synonyms, repeat words as often as necessary. • Avoid all inclusive expressions (such as “etc.”) • Be prepared to enforce the requirements that you write. Don’t write anything that you are not prepared to enforce. • Reference industry “standard” specifications wherever possible. (ASTM, AASHTO, ACI, AISC, etc…) • Use end-result (performance) rather than materials-methods (procedure) requirements where possible. • Don’t make a suggestion or give an explanation.

7. And Even More… • Be fair to all parties. Requirements should be fair, reasonable, and practical. • Seek the balance between omissions and irrelevant information. • Be knowledgeable about what you are writing. Obtain competent assistance when necessary. • Avoid proprietary items. • Know your audience: What do they know, how detailed must you get. • Coordinate the specifications with the drawings.

8. Be Organized • Establish a Table of Contents and Index. • Establish some type of numbering or reference system that can be easily used to reference individual specification components. • Use a consistent style format that makes the documents as easy to use as possible.

9. Writing Style • Traditionally, specifications are written in the indicative mood, either active or passive voice. • Active voice: The Contractor shall place the aggregate to a depth of 6 inches and compact it to a density of 95 percent. • Passive voice: The aggregate shall be placed to a depth of 6 inches and compacted to a density of 95 percent. • Several states have rewritten their standard specifications in the imperative mood, active voice. This style of writing replaces the lengthy “the Contractor shall” sentences with short sentences giving direct instructions. • Imperative mood, active voice: Place the aggregate to a depth of 6 inches and compact it to a density of 95 percent. (from CDOT)

10. Procedure vs. Performance • “Materials-methods (procedure) and end-result (performance) are the two basic types of construction specifications. • Materials-methods specifications describe in detail the materials, workmanship, and processes the Contractor is to use during construction. Materials-methods specifications restrain contractor innovation and obligate the owner to accept the work if the specified materials and processes are used. • End-result specifications describe the desired result or quality of the final product to be achieved. End-result specifications encourage contractor innovation and allow the owner to accept or reject the final product.” • “…specifications may include both types and, in some cases, a combination thereof. End-result specifications are preferred.” (from CDOT)

11. Example ofPerformance vs. Procedure • Let’s say that you are having important guest’s over this evening and you know that they will be in your kitchen. The floor has crumbs and other debris on it. You want to have your significant other or a child rectify the situation. You issue the specification in one of two ways: • “Sweep the floor.” • “Remove the debris from the floor so that the floor is clean and presentable.” • What is the difference?

12. Specifications • Often found in two places in the contract documents • A specification book, and • A set of “short specs” or “General Notes” found on the drawings. • On small projects, the General Notes may be sufficient.

13. Some Example General Notes CONCRETE ALL REINFORCED CONCRETE SHALL HAVE A MINIMUM 28-DAY COMPRESSIVE DESIGN STRENGTH OF f'c =4,000 PSI, REFER T0 SPECIFICATIONS FOR ADDITIONAL MATERIALS AND TESTING REQUIREMENTS.

14. Concrete Again… CONCRETE: MIXING AND PLACING OF ALL CONCRETE AND SELECTION OF MATERIALS SHALL BE IN ACCORDANCE WITH THE UNIFORM BUILDING CODE, 1989 EDITION, ALL CONCRETE, INCLUDING SLABS ON GROUND, SHALL HAVE SIKA "PLASTIMENT OR MASTER BUILDERS "POZZOLITE 300NR” ADDED IN ACCORDANCE WITH MANUFACTURERS DIRECTIONS. ALL CONCRETE EXPOSED T0 THE WEATHER SHALL CONTAIN AIR ADMIXTURES TO PRODUCE 4 T0 7 PERCENT ENTRAINED AIR. MAXIMUM SIZE OF AGGREGATE SHALL NOT BE MORE THAN 3/4 OF THE CLEAR DISTANCE BETWEEN REINFORCING BARS OR BETWEEN BARS AND SIDE FORMS. WATER/CEMENT RATIO AND CEMENT CONTENT SHALL BE AS FOLLOWS FOR VARIOUS CONCRETE STRENGTHS (f'c, BASED ON STANDARD CYLINDER TESTS) MIN. SACKS OF MAX. GALS. OF CEMENT/CU. YD. WATER/SACK MAX. f'c OF CONCRETE CEMENT SLUMP LOCATION 2,500 psi 5 7-l/2 3 SLABS ON GROUND 3,000 psi 5-l/2 7 4 ALL OTHER CONCRETE

15. And Again… CONCRETE Mixing, selection of materials and placing of all concrete shall conform to the requirements of the Uniform Building Code, 1979 Edition. An air entraining agent, conforming to ASTM Specification C260, shall be used in all concrete mixes for concrete work that is exposed to earth or weather. The amount of entraining air shall be 5% by volume with a tolerance of 1%. The Contractor shall submit a mix design for approval. All concrete shall be tested by an approved testing lab at 7 and 28 days and the results submitted for approval. Minimum concrete requirements at 28 days shall be as follows: CLASS AND USE 28 DAY f'c SLUMP SACKS/C.Y. Footings and mats 3000 p.s.i. 4-5” 5 * Slabs on grade 3000 p.s.i. 2-3" 5 * Structural concrete above ground floor 3000 p.s.i. 3-4" 5-1/2 * Precast concrete 3500 p.s.i. 3-4" 5-1/2 * Non-shrink grout 3000 p.s.i. dry pack --- Masonry grout 2000 p.s.i. 6-8" 5 *, ** Sidewalks and ext. stairs 2500 p.s.i. 3-4" 5 * * Type A water-reducing agent may be used to improve workability. ** Calcium chloride not permitted. Mixing and delivery shall conform with ASTM C94. When a truck mixer or agitator is approved for mixing or delivery of concrete, no water from the truck water system or elsewhere shall be added after the initial introduction of the mixing water for the batch except when on arrival at the job site the slump of the concrete is less than that specified. Such additional water to bring the slump within required limits shall be injected into the mixer. The drum shall be turned an additional 30 revolutions or more if necessary at mixing speed. Water shall not be added to the batch at any later time. Discharge of the concrete shall be completed within 1-1/2 hr., or before the drum has revolved 300 revolutions, whichever comes first, after the introduction of the mixing water to the cement and aggregates or the introduction of the cement to the aggregates. These limitations may be waived by the purchaser if the concrete is of such slump after the 1-1/2 hr. time or 300-revolution limit has been reached that it can be placed, without the addition of water, to the batch. In hot weather, or under conditions contributing to quick stiffening of the concrete, a time less than 1-1/2 hr. may be specified by the purchaser.