Foundry sand (FS) waste creates a serious solid waste management problem worldwide due to the high volumes produced, necessitating alternatives to landfilling. A possible route is its use in concrete; however, the current consensus is that FS can only be used for modest sand replacements, based mostly on evidence on concrete with clay-bound FS (greensand). Conversely, this study assessed salient properties of structural concrete with chemically bound FS (polymeric resin binder), for which there is very little information. Concrete mixes were prepared in which FS replaced regular concrete sand partially or fully. The results showed that unlike greensand, the tested chemically bound FS could replace regular concrete sand fully, giving highly workable mixes with good mechanical properties (compressive, splitting and flexural strengths and static modulus of elasticity) similar to those of mixes with regular concrete sand; the effect of FS content on these properties was not statistically significant. Durability in terms of water absorption, carbonation and alkali-silica reaction tests was not adversely affected. The possibility of using high contents of this type of FS in concrete (as opposed to greensand) gives promise for an additional outlet route for large quantities of this waste material with clear economic and environmental benefits.

This paper is both a criticism and extension of a small existing literature on procedural norms and tolerance which has been influential in several interpretations of American politics but which suffers from both conceptual and empirical shortcomings.The existing literature concludes that tolerance is not widely distributed in the American mass public: unpopular groups such as Communists or atheists would not be allowed political activity by most Americans despite supposed acceptance by all of the principle of minority rights. The literature suggests that hostile attitudes towards the issue or group involved prevents application of the tolerant general norm in specific instances.By failing to adequately measure or control for either issue orientation or general norms, however, the existing literature risks misrepresenting the actual extent and character of tolerance. This study discusses the weaknesses of the existing literature, describes how such weaknesses can be eliminated, and reports data which modify and expand the findings of past research for an updated set of issues, groups, and political acts.

No abstract

This paper is both a criticism and extension of a small existing literature on procedural norms and tolerance which has been influential in several interpretations of American politics but which suffers from both conceptual and empirical shortcomings.The existing literature concludes that tolerance is not widely distributed in the American mass public: unpopular groups such as Communists or atheists would not be allowed political activity by most Americans despite supposed acceptance by all of the principle of minority rights. The literature suggests that hostile attitudes towards the issue or group involved prevents application of the tolerant general norm in specific instances.By failing to adequately measure or control for either issue orientation or general norms, however, the existing literature risks misrepresenting the actual extent and character of tolerance. This study discusses the weaknesses of the existing literature, describes how such weaknesses can be eliminated, and reports data which modify and expand the findings of past research for an updated set of issues, groups, and political acts.

No abstract