Exam Cheat Sheet · Quick Reference

Arkansas Concrete - Residential Exam

Arkansas · PSI Services Contractor

Verified, not estimated. Every figure below is drawn from the official exam structure we maintain — question counts, passing standard and topic weighting. Practice questions are grounded in the source law with statute citations. We omit any figure we can't verify rather than guess at it.

Total questions

Passing score

70%

Exam time

75 min

Administered by

PSI Services Contractor

Format

Reference materials allowed

Arkansas State Portion 30 questions

Estimating 3 Q · 10%

Layout and Excavation 6 Q · 20%

Formwork 4 Q · 13%

Formwork safety requirements and failure preventionLateral pressure of concrete on forms (temperature, rate of placement, unit weight)Types of formwork systems (job-built, gang, flying table, slipform, jump form, ICF, stay-in-place)Form materials and hardware (plywood grades, lumber, steel, form ties, anchors, liners)Form design considerations and load calculationsForm removal timing and concrete strength requirementsShoring and reshoring procedures for multistory constructionFormwork tolerances and dimensional accuracy (ACI 117)

Reinforcing Steel 4 Q · 13%

General Concrete 9 Q · 30%

OSHA Safety 4 Q · 13%

Key Distinctions

Plan viewvsProfile view

Plan view is a bird's-eye overhead view showing the layout of the work area, while profile view is a horizontal cut-away (cross-section) along the alignment showing elevations, grades, and depths.

Pipe and Excavation Contracting, Page 105, Chapter 3 introduction, plan view/profile view definitions

SlipformsvsJump forms

Slipforms place concrete by extrusion as the forms are pulled or jacked vertically or horizontally slowly enough for the concrete to gain strength and hold its shape, while jump forms are stripped and re-set ("jumped") to the next level.

Contractor's Guide to Quality Concrete Construction (4th ed.), Chapter 5 — Types of Forms section

Payment bondvsPerformance bond

A payment bond guarantees all bills for labor, equipment, and materials are paid and liens discharged; a performance bond guarantees completion of the work.

Pipe and Excavation Contracting, Page 47

Form tie safety factor (2:1)vsForm anchor safety factor (3)

Form ties use a usual 2:1 safety factor (working load limited to one-half ultimate tensile strength), while form anchors require a minimum safety factor of 3 including live loads and impact because the concrete they are embedded in is often still green.

Contractor's Guide to Quality Concrete Construction (4th ed.), Page 66

Dozers (short haul)vsSelf-loading scrapers / loaders and trucks (longer haul)

For short haul distances from cut to fill, dozers are recommended; longer hauls use self-loading scrapers and long-distance hauling requires loaders and trucks (graders are used for very slight cuts and fills).

Pipe and Excavation Contracting, Pages 270-271

Wheeled backhoevsTrack excavator

A wheeled backhoe has a minimum effective digging cycle of about 10 seconds, while a small ¾-yard trackhoe is about 15 seconds and larger track excavators take 30 to 40 seconds per cycle; in the text's 1,230-ft job example the track excavator produced 50 LCY/hr versus 29 LCY/hr for the backhoe but its mobilization (about 10 percent of total job cost) made it unattractive.

Pipe and Excavation Contracting, Page 168

Calcium chloride acceleratorvsNon-chloride accelerator

Calcium chloride is an effective set accelerator but accelerates corrosion of reinforcing steel (and is not an effective antifreeze, lowering the freezing point only a few degrees), so non-chloride accelerators are more appropriate for steel-reinforced concrete.

Design and Control of Concrete Mixtures, 17th ed., Chapter 6 - Chemical Admixtures for Concrete, Page 129 (16th ed.: Pages 222-223)

Competent personvsEmployee qualified to operate equipment

A competent person can identify existing and predictable hazards and is authorized to take prompt corrective measures (and must make the frequent and regular job site inspections), while §1926.20(b)(4) separately requires that only employees qualified by training or experience be permitted to operate equipment and machinery.

OSHA 1926 CFR 29, §1926.32(f), Page 31

Employer with more than 10 employees (emergency action plan)vsEmployer with 10 or fewer employees

Under §1926.35(e)(3), an employer with 10 or fewer employees may communicate the emergency action plan orally and need not maintain a written plan.

OSHA 1926 CFR 29, §1926.35(e)(3)

PPE the employer must pay forvsNon-specialty safety-toe footwear and non-specialty prescription safety eyewear

Per §1926.95(d)(2), the employer is not required to pay for non-specialty safety-toe protective footwear (steel-toe shoes/boots) or non-specialty prescription safety eyewear provided the employer permits those items to be worn off the job site.

29 CFR 1926, Subpart E, §1926.95(d)(2)

Exposure Category F3 (freeze-thaw with deicing chemicals)vsExposure Category W1 (water contact, low permeability required)

F3 (freezing-and-thawing with frequent water exposure plus deicing chemicals) allows a maximum w/cm of 0.40 with minimum 5000 psi, while W1 allows a maximum w/cm of 0.50 with minimum 4000 psi.

Contractor's Guide to Quality Concrete Construction (4th ed.), Page 24 (Table 2.5)

Sulfate exposure class S2vsExpansive soil criteria

S2 is a concrete mixture requirement for dissolved sulfate between 1500 and 10,000 ppm (max w/cm 0.45, min 4500 psi), while expansive soil is a site/soil classification where a Plasticity Index of 15 or greater (ASTM D 4318) is one of four defining provisions.

Contractor's Guide to Quality Concrete Construction (4th ed.), Page 24 (Table 2.5)

Horizontal scalevsVertical scale

Utility site plans use two scales; usually the horizontal scale is ten times the vertical, but in the text's example 1 in = 40 ft horizontal and 1 in = 10 ft vertical gives a 4:1 ratio.

Pipe and Excavation Contracting, Page 109

Key Terms

Competent person OSHA 1926 CFR 29, §1926.32(f), Page 31

Per §1926.32(f), one who is capable of identifying existing and predictable hazards in the surroundings or working conditions that are unsanitary, hazardous, or dangerous to employees and who has authorization to take prompt corrective measures to eliminate them.

Accident prevention program inspections OSHA 1926 CFR 29, §1926.20(b)(2), Page 29

Per §1926.20(b)(2), programs shall provide for frequent and regular inspections of job sites, materials, and equipment made by competent persons designated by the employer; §1926.20(b)(1) makes initiating and maintaining such programs the employer's responsibility.

Emergency action plan (minimum elements) OSHA 1926 CFR 29, §1926.35(b), Page 33

Per §1926.35(b), minimum elements are emergency escape procedures, procedures for employees who remain for critical operations, procedures to account for all employees after evacuation, rescue and medical duties, preferred means of reporting emergencies, and names/titles of contact persons — a tool and equipment inventory is not required.

Safety training and education (§1926.21(b)) 29 CFR 1926, Page 30, §1926.21(b)(2)

The employer shall instruct each employee in recognition and avoidance of unsafe conditions and applicable regulations, and employees handling poisons, caustics, other harmful substances, flammable liquids, gases, or toxic materials must be instructed in safe handling and use, potential hazards, personal hygiene, and required protective measures.

Insulating equipment inspection and air test 29 CFR 1926, §1926.97(c)(2)(ii)

Per §1926.97(c)(2)(ii), insulating equipment shall be inspected for damage before each day's use and immediately after any incident reasonably suspected of causing damage, and insulating gloves shall be given an air test along with the inspection; rubber insulating blankets are electrically tested before first issue and every 12 months thereafter, upon indication the insulating value is suspect, and after repair.

Stairway/ladder access point 29 CFR 1926, §1926.1051(a)

Per §1926.1051(a), a stairway or ladder shall be provided at all personnel points of access with a break in elevation of 19 inches (48 cm) or more where no ramp, runway, sloped embankment, or personnel hoist is provided.

Prescriptive footing (one-story light-frame) Contractor's Guide to Quality Concrete Construction (4th ed.), Page 47 (Table 4.1)

Per Table 4.1 (adapted from 2015 IBC Table 1809.7), a footing supporting one floor of light-frame construction requires a minimum width of 12 inches (300 mm) and a minimum thickness of 6 inches (150 mm).

Minimum concrete cover (cast against earth) Contractor's Guide to Quality Concrete Construction (4th ed.), Page 100 (Table 6.3)

Per ACI 318 as cited in Table 6.3, cast-in-place concrete cast against and permanently exposed to earth, such as footings, requires a minimum cover of 3 inches (75 mm).

Formwork cost share Contractor's Guide to Quality Concrete Construction (4th ed.), Page 54

Formwork costs range from 35 to 60 percent of the cost of a concrete structure, making it one of the most significant cost components.

Lateral form pressure variables Contractor's Guide to Quality Concrete Construction (4th ed.), Page 70

The three most important variables influencing the lateral pressure fresh concrete exerts on forms are concrete temperature, rate of placement, and weight of concrete.

Form tie setback (architectural concrete) Contractor's Guide to Quality Concrete Construction (4th ed.), Page 66

Architectural concrete specifications often require that no metal be left closer than 1-1/2 inches (40 mm) to the surface to avoid rust stains.

Camber Contractor's Guide to Quality Concrete Construction (4th ed.), Page 77

A slight upward curvature intentionally built into a structural element or form to compensate for deflection under loads, shrinkage, and creep.

Wall form stripping time Contractor's Guide to Quality Concrete Construction (4th ed.), Page 81

In the absence of engineer-specified strength or time criteria, wall forms should remain in place 12 hours — the total (not necessarily consecutive) time during which air temperature is above 50°F (10°C); when temperatures stay below 50°F these times should be lengthened.

Bar support height tolerance Placing Reinforcing Bars (10th ed.), Chapter 10 — Bar Supports

A variation of plus or minus 1/8 inch from the specified nominal height (base to underside of the bar) is a normal construction tolerance for bar supports.

Escalation allowance Pipe and Excavation Contracting, Page 27

An allowance for the increase in costs of labor, materials, and equipment between the time the bid is submitted and the time work is done and paid for; especially important during high inflation.

Contingency allowance Pipe and Excavation Contracting, Page 273

An amount added before bidding a job with uncertain subsurface conditions (no boring logs) to cover possible problems and to cushion equipment rental costs when equipment sits idle.

Mobilization Pipe and Excavation Contracting, Page 60

A cost that is sometimes itemized as a separate bid item; if it is not, it must be included in the equipment cost calculations.

Front end loading (unbalanced bid) Pipe and Excavation Contracting, Pages 36-37

Padding markup onto items scheduled early in the project; if the owner cuts back those items the contractor loses the concentrated profit — the example shows cutting a loaded item 50% dropping overall markup from 20% to 10%.

Station number Pipe and Excavation Contracting, Page 111

A survey stake notation showing horizontal distance in multiples of 100 feet, with the figure left of the plus sign as hundreds of feet and the figure right of it as additional feet (e.g., Sta 2 + 50 = 250 feet from Sta 0 + 00).

Trench box placement in unstable soil Pipe and Excavation Contracting, Page 174

The bottom of the trench box should sit higher than the pipe — 2 to 3 feet higher is usually enough; too low and pulling the box disturbs bedding and new pipe, and more than 5 feet above the pipe makes the ditch unsafe.

Formulas to Know

Cubic yards of pipe bedding for a trenchTrench length (ft) × trench width (ft) × bedding depth (ft) ÷ 27 (27 cubic feet per cubic yard)

Square yards of filter fabric (worked example)Length (ft) × width (ft) ÷ 9 sq ft per sq yd; example: 250 ft × 15 ft = 3,750 sq ft ÷ 9 ≈ 416 sq yd

Cut/fill volume of one grid prism (Cross Section Method)

Average the cut or fill depths at the prism's four corners, then multiply by the base area; example Prism D: (2.3 + 0.9 + 0.8 + 2.3) averaged = 1.58 ft × 2,500 SF = 3,950 cubic feet

Station distance from starting pointDistance (ft) = (number left of the plus sign × 100) + number right of the plus sign; example Sta 2 + 50 = 250 ft

Horizontal-to-vertical scale ratio (worked example)

Horizontal scale ÷ vertical scale; example 1 in = 40 ft horizontal and 1 in = 10 ft vertical gives 4 to 1 (text notes the horizontal scale is usually ten times the vertical)

Contraction joint spacing, slab-on-ground (rule of thumb)Spacing in feet = 2-1/2 × slab thickness in inches; example: 6 in. slab → 2-1/2 × 6 = 15 ft

Formwork camber (rule of thumb)Camber 1/4 inch per 10 feet (6 mm per 3 m) of span

Form tie working load

Working load of new ties limited to one-half the ultimate tensile strength (usual 2:1 safety factor); form anchors use a minimum safety factor of 3 including live load and impact

Minimum permitted single strength test (Criteria B, f'c of 5000 psi or less)

Minimum single test = specified f'c − 500 psi; example: 4000 − 500 = 3500 psi, so a 3600 psi test is acceptable and any test below 3500 psi requires an investigation of structural adequacy

Nominal maximum aggregate size (worked example)

Not more than one-third the slab depth and not more than one-fifth the narrowest dimension of a vertical member; example: 4 in. slab ÷ 3 ≈ 1-1/3 in. governs over 12 in. ÷ 5 = 2.4 in.

Formwork design weight of concreteUse approximately 150 lb/ft³ (2400 kg/m³) for normalweight concrete

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