Concrete pumping and its effect on the air void system Related Information

Lloyd Keller - Academia.edu

Concrete pumping and its effect on the air void system more. by Lloyd Keller. Publisher: Springer Nature America, Inc Publication Name: Materials and Structures. Research Interests: Civil Engineering, Building, and Cement Concrete Composites

Appendix A Pavement Distress Types and Causes

to inadequate compaction. High air void contents are associated with more rapid aging and increased likelihood of ravelling. Increased asphalt film thickness can significantly reduce the rate of aging and offset the effects of high air voids.2 Surface softening and aggregate dislodging due to oil spillage are also classified as ravelling.7 A - 6

Effect of Air Entrained Concrete on Strength of Concrete

Effect of Air Entrainment on Flexural Strength of Concrete; 1. Effect of Air Entrainment on Concrete Compressive Strength Air entraining admixture is usually introduced when it is desired to increase concrete workability without affecting much reduction in compressive strength. It is claimed that, the place-ability of an air entrained concrete

Concrete Pumping and its Effect on the Air Void System - CORE

Abstract. Pumping is the most utilized concrete placement technique on construction sites around the globe. Despite being used since the 1960s, a large portion of the knowledge related to the understanding of the concrete pumping process-especially with a focus on the effect of pumping on the concrete air void system-was generated through experience, and thus creating a need for a research

Research - Concrete Pumping Effects on Entrained Air-Voids

Air entrainment and its effects in concrete • Aggregate

Influence of Pumping/Extrusion on the Air-Void System of

Up to10%cash back · Jul 05, 2018 · The particular effect of pumping on changes in the concrete air void system has been investigated in the past [ 5, 6, 7, 8, 9, 10 ]. The general belief within the North American concrete industry is that pumping reduces air content by two or three percent [ 11 ].

Hydraulics Trouble Shooting Guide

2. max pump pressure exceeded 3. charge pump defective 4. shaft seals or seals on suction side are defective 5. pump defective 6. pressure and return lines connected wrongly 7. control system oscillating 8. As 1 A 8 1. line mountings missing or loose 2. lines have been wrongly laid 3. ID too small 4. As 4 C As 4 A 5. return terminates above fluid

Air entrainment and concrete - USDA

half by entrained air. This re d u c e s c o n s i d e r ably the adverse effects of a higher water/cement ratio at the s u r face of slabs and of laitance f o r ming on concrete surf a c e s . Air al-so produces stickier, more cohesive c o n c r ete; as a result, less segre g a - tion is experienced and more attra c - …

Safety | American Concrete Pumping Association

The ACPA National Office, along with professional industry experts in the concrete pumping industry, have developed a variety of safety publications and materials to provide you with a wide array of knowledge for creating a safe working environment around concrete pumps on the job site. Download any of the FREE safety materials offered below or

A Professional's Handbook on Grouting and Concrete Repair

American Concrete Institute (ACI), are key organizations responsible for establishing expansion mechanisms have a significant effect on the successful use of grout products in the field, ACI 351.1R-99 is an important tool for owners, engineers, architects, Star Products, Inc. developed and introduced an Air Release System – a

Air Entrainment - an overview | ScienceDirect Topics

In air-entrained concrete, air voids are formed that intersect the capillaries at regular intervals, preferably at no more than 0.4 mm spacing. This equates to a void spacing factor of 0.2 mm (the maximum distance from any point in the capillary system to the surface of the nearest air bubble).

Slump adjustment is a fact of life for concrete

Slump adjustment is a fact of life for concrete contractors, but they should follow these guidelines for its use Variations in slump between trucks can be the result of many factors. Long delivery, waiting, and unloading times, for example, can decrease slump. Add water, if necessary, in accordance with ASTM C 94. Turn the drum an additional 30

Practical Considerations in Pump Suction Arrangements

truly bad designs can in some cases actually result in physical damage to the pump or its parts. The study of pump suction system configuration can be broken down into two parts: (1) suction piping and (2) suction source. Critical consideration must be given to both in order to properly design an effi-cient system.

4 Reasons You Have Entrained Air In Your Pumping System

Feb 05, 2015 · A SHORT LIST OF HOW AIR GETS IN THE SYSTEM. So how did air get inside of the system? Below is a list of just some of the ways air could be creeping inside. FREE FALLING DISCHARGE Free falling discharge, or the waterfall effect, is when liquid is discharged into a pit or tank near the pump suction line that draws fluid from the tank/pit.

Effect of w/c ratio on air-void system of foamed concrete

Aug 08, 2011 · A study was undertaken to investigate the effect of water to cementitious material (w/c) ratio (ranging from 0·22 to 0·60) on the air-void system (air content ranging from about 10 to 70%) of foamed concrete, and their effects on the mechanical properties of foamed concrete without sand.

Aggregates for Concrete

in concrete, aggregate properties affecting performance of the concrete, tests used to measure aggregate properties, and methods used to obtain test samples. Normalweight as well as lightweight aggregates are discussed. The measurement system used in this Bulletin is the Inter-national System of Units, or SI Units. Accordingly, readers

Research - Concrete Pumping Effects on Entrained Air-Voids

Air entrainment and its effects in concrete • Aggregate

Concrete Slab Surface Defects: Causes, Prevention, Repair

5. Avoid overworking the concrete, especially with vibrating screeds, jitterbugs, or bullfloats. Overworking causes aggregate to settle and bleed water and excess fines to rise. Properly vibrate to release entrapped air. 6. Do not attempt to seal (finish) the surface too soon. Use a wood bullfloat on non-air-entrained concrete to avoid early

Practical Considerations in Pump Suction Arrangements

truly bad designs can in some cases actually result in physical damage to the pump or its parts. The study of pump suction system configuration can be broken down into two parts: (1) suction piping and (2) suction source. Critical consideration must be given to both in order to properly design an effi-cient system.

4 Reasons You Have Entrained Air In Your Pumping System

Feb 05, 2015 · A SHORT LIST OF HOW AIR GETS IN THE SYSTEM. So how did air get inside of the system? Below is a list of just some of the ways air could be creeping inside. FREE FALLING DISCHARGE Free falling discharge, or the waterfall effect, is when liquid is discharged into a pit or tank near the pump suction line that draws fluid from the tank/pit.