Objective:

To design two concrete pavement mixtures optimized for hot and cold weather conditions, respectively. Students will apply principles of mixture design and proportioning to address the challenges posed by extreme weather conditions on concrete pavement performance.

Instructions:

Readings Required:

Reference Textbook: Chapter $7,$ "Mixture Design and Proportioning." This chapter will provide the foundational knowledge needed to understand the principles of concrete mixture design and the factors influencing the selection of materials and their proportions.

Design Task:

Students are required to design two different concrete pavement mixture proportions. One mixture should be optimized for hot weather conditions, and the other for cold weather conditions.

For each mixture, prepare a detailed table indicating the weights per unit volume $(1m^3)$ of each material used, including cement, water, different aggregates, and any chemical or mineral additives $($e$.$g$.,$ pozzolans$).$ Ensure the table includes the following columns: Ingredients, Weights $($kg$),$ Volume $($m$3)$ and Purpose$/$Reason for Selection.

Requirements for the Mixture Designs:

Hot Weather Conditions:

Consider factors such as accelerated curing, high evaporation rates, and thermal cracking.

Discuss the selection of materials and proportions to mitigate these issues, such as the use of water$-$reducing admixtures or the incorporation of fly ash or other mineral admixtures.

Cold Weather Conditions:

Address challenges like delayed setting times, frost damage, and the need for thermal insulation during curing.

Justify the inclusion of accelerators, air$-$entraining agents, or the use of special cement to overcome these challenges.

Report Content:

Introduction to mixture design and the impact of weather conditions on concrete pavement.

Detailed tables for each mixture design.

Calculation of the unit volume weights of the concretes.

Discussion on the selection of materials:

Why each material was chosen.

Why it is used in the specified amount.

The role of chemical and mineral additives in the mixtures.

Page $1$ of $2$

Conclusion summarizing the rationale behind each mixture design and its expected performance under the specified weather conditions.