56 resultados para Anderson, Marian (1897-1993) -- Portraits
Resumo:
The penetration of chloride ions from deicing salts into the portland cement concrete of bridge decks can cause corrosion and serious damage to the reinforcing steel. Concrete properties which prevent chloride penetration into the bridge deck and provide a good structural and economic wearing surface are desirable. A variety of mix designs have been tried in the past in search of improved performance and lower costs for bridge deck overlay concrete. A group of mixes with various designs have been tested in this project and results are being compared to determine which concrete mix appears to be the most cost effective and resistant to chloride penetration for bridge deck overlay use.
Resumo:
This report summarizes the findings of a research which was intended to evaluate the concrete strength and opening time for the full depth patching projects in Iowa under cold weather and whether or not cold water could be allowed in the mix. This research was performed both in the laboratory and in the field. The results indicated that with the present specification the concrete strength after five hours for two-lane patches which requires hot water and calcium chloride is about 1,600 psi. Hence, if a higher strength is desired, a longer curing time is required. Hot water will have to be used and water reducer is not recommended for two-lane patches. On the other hand, the concrete strength for multi-lane patches with either hot or cold water approaches 4,000 psi in less than 24 hours. There was only a slight difference in compressive strengths between the 24-hour and 36-hours curing times.
Resumo:
Two lanes of a major four-lane arterial street in Cedar Rapids, Iowa, needed reconstruction. Because of the traffic volume and the detour problem, closure of the intersections, even for 1 day was not feasible. Use of Fast Track concrete paving on the mainline portion of the project permitted achievement of the opening strength of 400 psi in less than 12 hr. Fast Track II, used for the intersections, achieved the opening strength of 350 psi in 6 to 7 hr. Flexural and compression specimens of two sections each in the Fast Track and Fast Track II sections were subjected to pulse velocity tests. Maturity curves were developed by monitoring the temperatures. Correlations were performed between the pulse velocity and flexural strength and between the maturity and flexural strength. The project established the feasibility of using Fast Track II to construct portland cement concrete pavement at night and opening the roadway to traffic the next day.
Resumo:
Technology News is a newsletter produced by the Iowa Department of Transportation to provide information to the transportation specialist in Iowa's cities and counties. Technology News is one of CTRE's primary avenues for exchanging transportation-related information with local agencies. The bimonthly newsletter gives an up-to-date look to the up-to-date information our 2,500+ readers have grown to expect.
Resumo:
Technology News is a newsletter produced by the Iowa Department of Transportation to provide information to the transportation specialist in Iowa's cities and counties. Technology News is one of CTRE's primary avenues for exchanging transportation-related information with local agencies. The bimonthly newsletter gives an up-to-date look to the up-to-date information our 2,500+ readers have grown to expect.
Resumo:
Technology News is a newsletter produced by the Iowa Department of Transportation to provide information to the transportation specialist in Iowa's cities and counties. Technology News is one of CTRE's primary avenues for exchanging transportation-related information with local agencies. The bimonthly newsletter gives an up-to-date look to the up-to-date information our 2,500+ readers have grown to expect.
Resumo:
Technology News is a newsletter produced by the Iowa Department of Transportation to provide information to the transportation specialist in Iowa's cities and counties. Technology News is one of CTRE's primary avenues for exchanging transportation-related information with local agencies. The bimonthly newsletter gives an up-to-date look to the up-to-date information our 2,500+ readers have grown to expect.
Resumo:
Technology News is a newsletter produced by the Iowa Department of Transportation to provide information to the transportation specialist in Iowa's cities and counties. Technology News is one of CTRE's primary avenues for exchanging transportation-related information with local agencies. The bimonthly newsletter gives an up-to-date look to the up-to-date information our 2,500+ readers have grown to expect.
Resumo:
Technology News is a newsletter produced by the Iowa Department of Transportation to provide information to the transportation specialist in Iowa's cities and counties. Technology News is one of CTRE's primary avenues for exchanging transportation-related information with local agencies. The bimonthly newsletter gives an up-to-date look to the up-to-date information our 2,500+ readers have grown to expect.
Resumo:
Technology News is a newsletter produced by the Iowa Department of Transportation to provide information to the transportation specialist in Iowa's cities and counties. Technology News is one of CTRE's primary avenues for exchanging transportation-related information with local agencies. The bimonthly newsletter gives an up-to-date look to the up-to-date information our 2,500+ readers have grown to expect.
Resumo:
Technology News is a newsletter produced by the Iowa Department of Transportation to provide information to the transportation specialist in Iowa's cities and counties. Technology News is one of CTRE's primary avenues for exchanging transportation-related information with local agencies. The bimonthly newsletter gives an up-to-date look to the up-to-date information our 2,500+ readers have grown to expect.
Resumo:
Technology News is a newsletter produced by the Iowa Department of Transportation to provide information to the transportation specialist in Iowa's cities and counties. Technology News is one of CTRE's primary avenues for exchanging transportation-related information with local agencies. The bimonthly newsletter gives an up-to-date look to the up-to-date information our 2,500+ readers have grown to expect.
Resumo:
The purpose of this document is to provide the General Assembly with information related to FY General Fund estimated receipts and the Governor’s recommendations. This information provides an overall summary of the State budget and is intended to help the General Assembly take a proactive approach toward the budgeting process.
Resumo:
The purpose of this document is to provide the General Assembly with information related to FY General Fund estimated receipts and the Governor’s recommendations. This information provides an overall summary of the State budget and is intended to help the General Assembly take a proactive approach toward the budgeting process.
Resumo:
The crack and seat (C & S) method of rehabilitating concrete pavements has been proposed to reduce the incidence of reflective cracking in asphalt overlays. These cracked pieces help reduce the thermal effects on lateral joint movement while the seating of slab pieces reduces vertical movement. This 1986 project demonstrated that a 0.6 m x 0.9 m (2 ft x 3 ft) cracking pattern was optimal to retard reflective cracking in an asphalt overlay. The best performance among three C & S test sections was section 4 with a 0.6 m x 0.9 m (2 ft x 3 ft) cracking pattern and 7.6 cm (3 in) overlay. Structural ratings determined from the Road Rater™ indicated little difference between each C & S section with varying AC thicknesses and crack spacings. Although reflection cracking is reduced in the early years after construction, the effectiveness of the C & S method diminishes over time.
