We have been building an outdoor kitchen and subsequently purchased many different types of concrete products. I have noticed the cement, mortar, and grout are very similar products. What is the fundamental difference between these products (besides price and location)?
The primary differences are texture (grit content), and activator (the chemical used to harden the product). Also, there are boding properties associated with mortar and grout that standard concrete does not posses, mortar being the strongest (used for affixing tile to a subfloor or wall).
cement is an ingredient in mortar, grout and concrete. It can be used on its own, or mixed with aggregate (sand or crushed rock) of different grades to produce any of the above three. Mortar has a fairly fine aggregate mixed in, when compared to concrete. Grout can come in sanded or unsanded forms and have different colorants added.
The correct way is to chip out as much loose as possible with breaking any stones loose. Then fill in with mortar, not grout. grout is for small cracks. Also, it will be stronger longer lasting fix if the new mortar is continuous, connecting all around the stones.
Cement: Grey powder. Very corrosive. Beware. Chemically reacts with water (including your skin and eys). Mortar: 1 part Cement + 3 parts Sand (usually) used for building brick structures. Concrete: cement + sand + pebbles for added strength. Grout: Usually used to fill the gaps between tiles. A fine paste that sets hard.
Cement is a general building material -- like concrete. Mortar is the adhesive that sticks tiles (ceramic usually but it could be marble or even granite tiles) to the underlayment (the underlayment could be cement, cement board that his screwed to a wood sub-floor, etc.). It may be cement based but then have different additives. For an outdoor kitchen counter you will probably use a plywood or OSB sheet, then a 1/4 inch thick cement board and then stick your tiles on with a mortar that has a polymer additive because of the temperature changes Grout is what is used to fill the joints between the tiles after the mortar is dry. It is waterproof (do not use mortar in between tiles it is not waterproof and may wash away!) Sanded grout has more substance, e.g. will fill more, and is needed if the joints are greater than 1/4 inch or so..such as for large floor tiles Non-sanded grout is used for thin tile spaces...1/8 inch or less like small bathroom wall tiles.
